CHEM 122 - GENERAL CHEMISTRY II -
Atoms Question Bank
Question 1
Step-by-step solution: 1. The Rutherford model describes the structure of
an atom as mostly empty space with a dense, positively charged nucleus at
the center. 2. The nucleus contains protons, which have a positive charge,
and neutrons, which have no charge. 3. Electrons, which have a negative
charge, orbit the nucleus in distinct energy levels or shells. 4. The number of
protons in the nucleus determines the atomic number of the atom, which also
equals the number of electrons in a neutral atom. 5. Electrons are attracted
to the positively charged nucleus by the electromagnetic force, which keeps
them in orbit around the nucleus. 6. The Rutherford model provided a major
advancement in understanding the structure of atoms, but it was later refined
by the Bohr model and then by quantum mechanics.Question 1: Describe
the structure of an atom according to the Rutherford model.
Step-by-step solution: 1. The Rutherford model describes the
structure of an atom as mostly empty space with a dense, positively
charged nucleus at the center. 2. The nucleus contains protons,
which have a positive charge, and neutrons, which have no charge. 3.
Electrons, which have a negative charge, orbit the nucleus in distinct
energy levels or shells. 4. The number of protons in the nucleus deter-
mines the atomic number of the atom, which also equals the number
of electrons in a neutral atom. 5. Electrons are attracted to the
positively charged nucleus by the electromagnetic force, which keeps
them in orbit around the nucleus. 6. The Rutherford model provided
a major advancement in understanding the structure of atoms, but it
was later refined by the Bohr model and then by quantum mechanics.
Question 2
A certain element has an atomic number of 20.
a) How many protons does this element have? b) How many elec-
trons does this element have if it is electrically neutral? c) What is
the symbol of this element?
1
Step-by-step solutions: a) The atomic number of an element rep-
resents the number of protons in its nucleus. Therefore, this element
with an atomic number of 20 has 20 protons.
b) For an electrically neutral atom, the number of protons in the
nucleus must be equal to the number of electrons surrounding the
nucleus. Hence, this element with 20 protons will also have 20 elec-
trons.
c) The symbol of an element is derived from its name or Latin
name. For the element with 20 protons (atomic number), the symbol
is Ca which represents Calcium.Question 2:
A certain element has an atomic number of 20.
a) How many protons does this element have? b) How many elec-
trons does this element have if it is electrically neutral? c) What is
the symbol of this element?
Step-by-step solutions: a) The atomic number of an element rep-
resents the number of protons in its nucleus. Therefore, this element
with an atomic number of 20 has 20 protons.
b) For an electrically neutral atom, the number of protons in the
nucleus must be equal to the number of electrons surrounding the
nucleus. Hence, this element with 20 protons will also have 20 elec-
trons.
c) The symbol of an element is derived from its name or Latin
name. For the element with 20 protons (atomic number), the symbol
is Ca which represents Calcium.
Question 3
Step-by-step solutions: a) Since the atom is neutral, the number
of protons in the nucleus must be equal to the number of electrons
surrounding the nucleus. Therefore, the atom has 18 protons.
b) The atomic number of an element is equal to the number of
protons in the nucleus. So, the atomic number of this atom is also
18.
c) To determine the number of electrons in the outermost energy
level (valence electrons), you can refer to the periodic table and find
the group number of the element with an atomic number of 18. In
this case, element number 18 is in group 18 of the periodic table,
which means it has 8 valence electrons.Question 3: Given a neutral
atom with 18 electrons, answer the following questions: a) How many
protons are in the nucleus of this atom? b) What is the atomic
number of this atom? c) How many electrons are in the outermost
energy level of this atom?
Step-by-step solutions: a) Since the atom is neutral, the number
of protons in the nucleus must be equal to the number of electrons
surrounding the nucleus. Therefore, the atom has 18 protons.
2
b) The atomic number of an element is equal to the number of
protons in the nucleus. So, the atomic number of this atom is also
18.
c) To determine the number of electrons in the outermost energy
level (valence electrons), you can refer to the periodic table and find
the group number of the element with an atomic number of 18. In
this case, element number 18 is in group 18 of the periodic table,
which means it has 8 valence electrons.
Question 4
Step-by-step solution: 1. The atomic number (Z) of an element
represents the number of protons in the nucleus. 2. The atomic
number of the element is given as 8. Therefore, the number of protons
(P) in the nucleus is 8. 3. The number of electrons in a neutral atom
is equal to the number of protons. So, the number of electrons (E)
is also 8. 4. To determine the number of neutrons (N), you need
to use the mass number formula: Mass number (A) = Number of
protons (P) + Number of neutrons (N). 5. If the atom is neutral,
the number of protons equals the number of electrons, which means
the charge is balanced. 6. Since the element is not specified, the
exact mass number is unknown. Therefore, you typically assume a
standard atomic weight for oxygen. 7. Oxygen usually has a standard
atomic weight of approximately 16. This means the mass number of
this oxygen atom would be approximately 16. 8. Using the mass
number formula, 16 = 8 protons + Number of neutrons. 9. Solving
for the number of neutrons: Number of neutrons = 16 - 8 = 8. 10.
Therefore, the atom of the element with atomic number 8 contains
8 protons, 8 electrons, and 8 neutrons.Question 4: An element has
an atomic number of 8. Determine the number of protons, electrons,
and neutrons in an atom of this element.
Step-by-step solution: 1. The atomic number (Z) of an element
represents the number of protons in the nucleus. 2. The atomic
number of the element is given as 8. Therefore, the number of protons
(P) in the nucleus is 8. 3. The number of electrons in a neutral atom
is equal to the number of protons. So, the number of electrons (E)
is also 8. 4. To determine the number of neutrons (N), you need
to use the mass number formula: Mass number (A) = Number of
protons (P) + Number of neutrons (N). 5. If the atom is neutral,
the number of protons equals the number of electrons, which means
the charge is balanced. 6. Since the element is not specified, the
exact mass number is unknown. Therefore, you typically assume a
standard atomic weight for oxygen. 7. Oxygen usually has a standard
atomic weight of approximately 16. This means the mass number of
this oxygen atom would be approximately 16. 8. Using the mass
3
number formula, 16 = 8 protons + Number of neutrons. 9. Solving
for the number of neutrons: Number of neutrons = 16 - 8 = 8. 10.
Therefore, the atom of the element with atomic number 8 contains 8
protons, 8 electrons, and 8 neutrons.
Question 5
Step 1: Identify the atomic number and mass number of the car-
bon atom. - The atomic number of carbon is 6, which indicates the
number of protons. - The mass number is the sum of protons and
neutrons, which is 6 protons + 6 neutrons = 12.
Step 2: Atomic mass calculation. - The atomic mass is the weighted
average of all naturally occurring isotopes of an element. - Since
carbon has several isotopes, we need to consider their relative abun-
dances to calculate the atomic mass. - The most abundant isotope of
carbon is carbon-12 with an abundance of 98.89
Step 3: Calculate the atomic mass of carbon. - To calculate the
atomic mass, multiply the abundance of each isotope by its mass
number, then sum the results. - Atomic mass = (0.9889 * 12) +
(0.0111 * 13) - Atomic mass = 11.8668 + 0.1443 - Atomic mass 12.01
Therefore, the atomic mass of the carbon atom with 6 protons and
6 neutrons is approximately 12.01.Question 5: An atom of carbon has
6 protons and 6 neutrons. Calculate the atomic mass of this carbon
atom.
Step 1: Identify the atomic number and mass number of the car-
bon atom. - The atomic number of carbon is 6, which indicates the
number of protons. - The mass number is the sum of protons and
neutrons, which is 6 protons + 6 neutrons = 12.
Step 2: Atomic mass calculation. - The atomic mass is the weighted
average of all naturally occurring isotopes of an element. - Since
carbon has several isotopes, we need to consider their relative abun-
dances to calculate the atomic mass. - The most abundant isotope of
carbon is carbon-12 with an abundance of 98.89
Step 3: Calculate the atomic mass of carbon. - To calculate the
atomic mass, multiply the abundance of each isotope by its mass
number, then sum the results. - Atomic mass = (0.9889 * 12) +
(0.0111 * 13) - Atomic mass = 11.8668 + 0.1443 - Atomic mass 12.01
Therefore, the atomic mass of the carbon atom with 6 protons and
6 neutrons is approximately 12.01.
Question 6
Step-by-step solution: 1. The atomic number of an atom indicates
the number of protons it has. In this case, the carbon atom has 6
4
protons. 2. The number of neutrons in an atom can be calculated by
subtracting the atomic number from the mass number. In this case,
the carbon atom has 6 neutrons. 3. The mass number of an atom is
the sum of its protons and neutrons. Therefore, the mass number of
the carbon atom is 6 (protons) + 6 (neutrons) = 12. 4. The number
of electrons in a neutral atom is equal to the number of protons. Since
the carbon atom has 6 protons, it also has 6 electrons.Question 6: A
carbon atom has 6 protons, 6 neutrons, and 6 electrons.
Step-by-step solution: 1. The atomic number of an atom indicates
the number of protons it has. In this case, the carbon atom has 6
protons. 2. The number of neutrons in an atom can be calculated
by subtracting the atomic number from the mass number. In this
case, the carbon atom has 6 neutrons. 3. The mass number of an
atom is the sum of its protons and neutrons. Therefore, the mass
number of the carbon atom is 6 (protons) + 6 (neutrons) = 12. 4.
The number of electrons in a neutral atom is equal to the number of
protons. Since the carbon atom has 6 protons, it also has 6 electrons.
Question 7
Step-by-step solution: 1. The atomic number of an element is
equal to the number of protons in its nucleus. Since the carbon atom
has 6 protons, its atomic number is 6. 2. The mass number of an
element is equal to the sum of the number of protons and neutrons
in its nucleus. In this case, the carbon atom has 6 protons and 6
neutrons, so its mass number is 6 + 6 = 12. 3. The number of
protons in an atom is always equal to its atomic number. Therefore,
the carbon atom has 6 protons. 4. The number of neutrons in an
atom is equal to the mass number minus the atomic number. So, the
carbon atom has 12 - 6 = 6 neutrons. 5. The number of electrons in
a neutral atom is equal to the number of protons. Since the carbon
atom has 6 protons, it also has 6 electrons.Question 7: A carbon
atom has 6 protons, 6 neutrons, and 6 electrons. Determine the
atomic number, mass number, and the number of protons, neutrons,
and electrons in this carbon atom.
Step-by-step solution: 1. The atomic number of an element is
equal to the number of protons in its nucleus. Since the carbon atom
has 6 protons, its atomic number is 6. 2. The mass number of an
element is equal to the sum of the number of protons and neutrons
in its nucleus. In this case, the carbon atom has 6 protons and 6
neutrons, so its mass number is 6 + 6 = 12. 3. The number of
protons in an atom is always equal to its atomic number. Therefore,
the carbon atom has 6 protons. 4. The number of neutrons in an
atom is equal to the mass number minus the atomic number. So, the
carbon atom has 12 - 6 = 6 neutrons. 5. The number of electrons in
5
a neutral atom is equal to the number of protons. Since the carbon
atom has 6 protons, it also has 6 electrons.
Question 8
Step 1: Identify the atomic number and mass number - Atomic
number (Z) = 20 - Mass number (A) = 40
Step 2: Determine the number of protons (p+) - The number of
protons is equal to the atomic number p+ = Z p+ = 20
Step 3: Find the number of neutrons (n0) - Neutrons can be cal-
culated by subtracting the number of protons from the mass number
n0 = A - p+ n0 = 40 - 20 n0 = 20
Step 4: Calculate the number of electrons (e-) - For a neutral
atom, the number of electrons is equal to the number of protons e-
= p+ e- = 20
Answer: The atom has: - 20 protons - 20 neutrons - 20 electron-
sQuestion 8: Calculate the number of protons, neutrons, and elec-
trons in an atom with the following information: - Atomic number =
20 - Mass number = 40
Step 1: Identify the atomic number and mass number - Atomic
number (Z) = 20 - Mass number (A) = 40
Step 2: Determine the number of protons (p+) - The number of
protons is equal to the atomic number p+ = Z p+ = 20
Step 3: Find the number of neutrons (n0) - Neutrons can be cal-
culated by subtracting the number of protons from the mass number
n0 = A - p+ n0 = 40 - 20 n0 = 20
Step 4: Calculate the number of electrons (e-) - For a neutral
atom, the number of electrons is equal to the number of protons e-
= p+ e- = 20
Answer: The atom has: - 20 protons - 20 neutrons - 20 electrons
Question 9
Step 1: Determine the atomic number: The atomic number is
equal to the number of protons in an atom. In this case, the atom
has 6 protons. Therefore, the atomic number is 6.
Step 2: Determine the mass number: The mass number is equal
to the sum of the number of protons and neutrons in an atom. In this
case, the atom has 6 protons and 6 neutrons. Therefore, the mass
number is 6 + 6 = 12.
Step 3: Determine the symbol of the atom: The symbol of an
element is determined by using the atomic number and the mass
number. The symbol is written as follows:
Symbol =element’s symbol −atomic number −mass number
6
In this case, the element is carbon with an atomic number of 6 and
a mass number of 12. Therefore, the symbol of the atom is:
Symbol =C−6−12
Symbol =12
6C
Thus, the atomic number is 6, the mass number is 12, and the
symbol of the atom is 12
6C.Question 9: An atom has 6 protons, 6 neu-
trons, and 6 electrons. Determine the atomic number, mass number,
and the symbol of the atom.
Step 1: Determine the atomic number: The atomic number is
equal to the number of protons in an atom. In this case, the atom
has 6 protons. Therefore, the atomic number is 6.
Step 2: Determine the mass number: The mass number is equal
to the sum of the number of protons and neutrons in an atom. In this
case, the atom has 6 protons and 6 neutrons. Therefore, the mass
number is 6 + 6 = 12.
Step 3: Determine the symbol of the atom: The symbol of an
element is determined by using the atomic number and the mass
number. The symbol is written as follows:
Symbol =element’s symbol −atomic number −mass number
In this case, the element is carbon with an atomic number of 6 and
a mass number of 12. Therefore, the symbol of the atom is:
Symbol =C−6−12
Symbol =12
6C
Thus, the atomic number is 6, the mass number is 12, and the
symbol of the atom is 12
6C.
Question 10
Step-by-step solution: 1. An atom is the smallest unit of mat-
ter that retains the properties of an element, consisting of a nucleus
containing positively charged protons and uncharged neutrons, sur-
rounded by negatively charged electrons. 2. A molecule is a group of
two or more atoms bonded together, representing the smallest unit of
a compound that retains the chemical properties of that compound.
3. Atoms of different elements combine to form molecules through
chemical bonding, while atoms of the same element can also bond to
form molecules. 4. The properties of an atom depend on the number
of protons, neutrons, and electrons it contains, while the properties
of a molecule depend on the types and arrangement of atoms within
7
Step-by-step solutions: a) The atomic number of an element rep-
resents the number of protons in its nucleus. Therefore, this element
with an atomic number of 20 has 20 protons.
b) For an electrically neutral atom, the number of protons in the
nucleus must be equal to the number of electrons surrounding the
nucleus. Hence, this element with 20 protons will also have 20 elec-
trons.
c) The symbol of an element is derived from its name or Latin
name. For the element with 20 protons (atomic number), the symbol
is Ca which represents Calcium.Question 2:
A certain element has an atomic number of 20.
a) How many protons does this element have? b) How many elec-
trons does this element have if it is electrically neutral? c) What is
the symbol of this element?
Step-by-step solutions: a) The atomic number of an element rep-
resents the number of protons in its nucleus. Therefore, this element
with an atomic number of 20 has 20 protons.
b) For an electrically neutral atom, the number of protons in the
nucleus must be equal to the number of electrons surrounding the
nucleus. Hence, this element with 20 protons will also have 20 elec-
trons.
c) The symbol of an element is derived from its name or Latin
name. For the element with 20 protons (atomic number), the symbol
is Ca which represents Calcium.
Question 3
Step-by-step solutions: a) Since the atom is neutral, the number
of protons in the nucleus must be equal to the number of electrons
surrounding the nucleus. Therefore, the atom has 18 protons.
b) The atomic number of an element is equal to the number of
protons in the nucleus. So, the atomic number of this atom is also
18.
c) To determine the number of electrons in the outermost energy
level (valence electrons), you can refer to the periodic table and find
the group number of the element with an atomic number of 18. In
this case, element number 18 is in group 18 of the periodic table,
which means it has 8 valence electrons.Question 3: Given a neutral
atom with 18 electrons, answer the following questions: a) How many
protons are in the nucleus of this atom? b) What is the atomic
number of this atom? c) How many electrons are in the outermost
energy level of this atom?
Step-by-step solutions: a) Since the atom is neutral, the number
of protons in the nucleus must be equal to the number of electrons
surrounding the nucleus. Therefore, the atom has 18 protons.
2
b) The atomic number of an element is equal to the number of
protons in the nucleus. So, the atomic number of this atom is also
18.
c) To determine the number of electrons in the outermost energy
level (valence electrons), you can refer to the periodic table and find
the group number of the element with an atomic number of 18. In
this case, element number 18 is in group 18 of the periodic table,
which means it has 8 valence electrons.
Question 4
Step-by-step solution: 1. The atomic number (Z) of an element
represents the number of protons in the nucleus. 2. The atomic
number of the element is given as 8. Therefore, the number of protons
(P) in the nucleus is 8. 3. The number of electrons in a neutral atom
is equal to the number of protons. So, the number of electrons (E)
is also 8. 4. To determine the number of neutrons (N), you need
to use the mass number formula: Mass number (A) = Number of
protons (P) + Number of neutrons (N). 5. If the atom is neutral,
the number of protons equals the number of electrons, which means
the charge is balanced. 6. Since the element is not specified, the
exact mass number is unknown. Therefore, you typically assume a
standard atomic weight for oxygen. 7. Oxygen usually has a standard
atomic weight of approximately 16. This means the mass number of
this oxygen atom would be approximately 16. 8. Using the mass
number formula, 16 = 8 protons + Number of neutrons. 9. Solving
for the number of neutrons: Number of neutrons = 16 - 8 = 8. 10.
Therefore, the atom of the element with atomic number 8 contains
8 protons, 8 electrons, and 8 neutrons.Question 4: An element has
an atomic number of 8. Determine the number of protons, electrons,
and neutrons in an atom of this element.
Step-by-step solution: 1. The atomic number (Z) of an element
represents the number of protons in the nucleus. 2. The atomic
number of the element is given as 8. Therefore, the number of protons
(P) in the nucleus is 8. 3. The number of electrons in a neutral atom
is equal to the number of protons. So, the number of electrons (E)
is also 8. 4. To determine the number of neutrons (N), you need
to use the mass number formula: Mass number (A) = Number of
protons (P) + Number of neutrons (N). 5. If the atom is neutral,
the number of protons equals the number of electrons, which means
the charge is balanced. 6. Since the element is not specified, the
exact mass number is unknown. Therefore, you typically assume a
standard atomic weight for oxygen. 7. Oxygen usually has a standard
atomic weight of approximately 16. This means the mass number of
this oxygen atom would be approximately 16. 8. Using the mass
3
number formula, 16 = 8 protons + Number of neutrons. 9. Solving
for the number of neutrons: Number of neutrons = 16 - 8 = 8. 10.
Therefore, the atom of the element with atomic number 8 contains 8
protons, 8 electrons, and 8 neutrons.
Question 5
Step 1: Identify the atomic number and mass number of the car-
bon atom. - The atomic number of carbon is 6, which indicates the
number of protons. - The mass number is the sum of protons and
neutrons, which is 6 protons + 6 neutrons = 12.
Step 2: Atomic mass calculation. - The atomic mass is the weighted
average of all naturally occurring isotopes of an element. - Since
carbon has several isotopes, we need to consider their relative abun-
dances to calculate the atomic mass. - The most abundant isotope of
carbon is carbon-12 with an abundance of 98.89
Step 3: Calculate the atomic mass of carbon. - To calculate the
atomic mass, multiply the abundance of each isotope by its mass
number, then sum the results. - Atomic mass = (0.9889 * 12) +
(0.0111 * 13) - Atomic mass = 11.8668 + 0.1443 - Atomic mass 12.01
Therefore, the atomic mass of the carbon atom with 6 protons and
6 neutrons is approximately 12.01.Question 5: An atom of carbon has
6 protons and 6 neutrons. Calculate the atomic mass of this carbon
atom.
Step 1: Identify the atomic number and mass number of the car-
bon atom. - The atomic number of carbon is 6, which indicates the
number of protons. - The mass number is the sum of protons and
neutrons, which is 6 protons + 6 neutrons = 12.
Step 2: Atomic mass calculation. - The atomic mass is the weighted
average of all naturally occurring isotopes of an element. - Since
carbon has several isotopes, we need to consider their relative abun-
dances to calculate the atomic mass. - The most abundant isotope of
carbon is carbon-12 with an abundance of 98.89
Step 3: Calculate the atomic mass of carbon. - To calculate the
atomic mass, multiply the abundance of each isotope by its mass
number, then sum the results. - Atomic mass = (0.9889 * 12) +
(0.0111 * 13) - Atomic mass = 11.8668 + 0.1443 - Atomic mass 12.01
Therefore, the atomic mass of the carbon atom with 6 protons and
6 neutrons is approximately 12.01.
Question 6
Step-by-step solution: 1. The atomic number of an atom indicates
the number of protons it has. In this case, the carbon atom has 6
4
protons. 2. The number of neutrons in an atom can be calculated by
subtracting the atomic number from the mass number. In this case,
the carbon atom has 6 neutrons. 3. The mass number of an atom is
the sum of its protons and neutrons. Therefore, the mass number of
the carbon atom is 6 (protons) + 6 (neutrons) = 12. 4. The number
of electrons in a neutral atom is equal to the number of protons. Since
the carbon atom has 6 protons, it also has 6 electrons.Question 6: A
carbon atom has 6 protons, 6 neutrons, and 6 electrons.
Step-by-step solution: 1. The atomic number of an atom indicates
the number of protons it has. In this case, the carbon atom has 6
protons. 2. The number of neutrons in an atom can be calculated
by subtracting the atomic number from the mass number. In this
case, the carbon atom has 6 neutrons. 3. The mass number of an
atom is the sum of its protons and neutrons. Therefore, the mass
number of the carbon atom is 6 (protons) + 6 (neutrons) = 12. 4.
The number of electrons in a neutral atom is equal to the number of
protons. Since the carbon atom has 6 protons, it also has 6 electrons.
Question 7
Step-by-step solution: 1. The atomic number of an element is
equal to the number of protons in its nucleus. Since the carbon atom
has 6 protons, its atomic number is 6. 2. The mass number of an
element is equal to the sum of the number of protons and neutrons
in its nucleus. In this case, the carbon atom has 6 protons and 6
neutrons, so its mass number is 6 + 6 = 12. 3. The number of
protons in an atom is always equal to its atomic number. Therefore,
the carbon atom has 6 protons. 4. The number of neutrons in an
atom is equal to the mass number minus the atomic number. So, the
carbon atom has 12 - 6 = 6 neutrons. 5. The number of electrons in
a neutral atom is equal to the number of protons. Since the carbon
atom has 6 protons, it also has 6 electrons.Question 7: A carbon
atom has 6 protons, 6 neutrons, and 6 electrons. Determine the
atomic number, mass number, and the number of protons, neutrons,
and electrons in this carbon atom.
Step-by-step solution: 1. The atomic number of an element is
equal to the number of protons in its nucleus. Since the carbon atom
has 6 protons, its atomic number is 6. 2. The mass number of an
element is equal to the sum of the number of protons and neutrons
in its nucleus. In this case, the carbon atom has 6 protons and 6
neutrons, so its mass number is 6 + 6 = 12. 3. The number of
protons in an atom is always equal to its atomic number. Therefore,
the carbon atom has 6 protons. 4. The number of neutrons in an
atom is equal to the mass number minus the atomic number. So, the
carbon atom has 12 - 6 = 6 neutrons. 5. The number of electrons in
5
a neutral atom is equal to the number of protons. Since the carbon
atom has 6 protons, it also has 6 electrons.
Question 8
Step 1: Identify the atomic number and mass number - Atomic
number (Z) = 20 - Mass number (A) = 40
Step 2: Determine the number of protons (p+) - The number of
protons is equal to the atomic number p+ = Z p+ = 20
Step 3: Find the number of neutrons (n0) - Neutrons can be cal-
culated by subtracting the number of protons from the mass number
n0 = A - p+ n0 = 40 - 20 n0 = 20
Step 4: Calculate the number of electrons (e-) - For a neutral
atom, the number of electrons is equal to the number of protons e-
= p+ e- = 20
Answer: The atom has: - 20 protons - 20 neutrons - 20 electron-
sQuestion 8: Calculate the number of protons, neutrons, and elec-
trons in an atom with the following information: - Atomic number =
20 - Mass number = 40
Step 1: Identify the atomic number and mass number - Atomic
number (Z) = 20 - Mass number (A) = 40
Step 2: Determine the number of protons (p+) - The number of
protons is equal to the atomic number p+ = Z p+ = 20
Step 3: Find the number of neutrons (n0) - Neutrons can be cal-
culated by subtracting the number of protons from the mass number
n0 = A - p+ n0 = 40 - 20 n0 = 20
Step 4: Calculate the number of electrons (e-) - For a neutral
atom, the number of electrons is equal to the number of protons e-
= p+ e- = 20
Answer: The atom has: - 20 protons - 20 neutrons - 20 electrons
Question 9
Step 1: Determine the atomic number: The atomic number is
equal to the number of protons in an atom. In this case, the atom
has 6 protons. Therefore, the atomic number is 6.
Step 2: Determine the mass number: The mass number is equal
to the sum of the number of protons and neutrons in an atom. In this
case, the atom has 6 protons and 6 neutrons. Therefore, the mass
number is 6 + 6 = 12.
Step 3: Determine the symbol of the atom: The symbol of an
element is determined by using the atomic number and the mass
number. The symbol is written as follows:
Symbol =element’s symbol −atomic number −mass number
6
In this case, the element is carbon with an atomic number of 6 and
a mass number of 12. Therefore, the symbol of the atom is:
Symbol =C−6−12
Symbol =12
6C
Thus, the atomic number is 6, the mass number is 12, and the
symbol of the atom is 12
6C.Question 9: An atom has 6 protons, 6 neu-
trons, and 6 electrons. Determine the atomic number, mass number,
and the symbol of the atom.
Step 1: Determine the atomic number: The atomic number is
equal to the number of protons in an atom. In this case, the atom
has 6 protons. Therefore, the atomic number is 6.
Step 2: Determine the mass number: The mass number is equal
to the sum of the number of protons and neutrons in an atom. In this
case, the atom has 6 protons and 6 neutrons. Therefore, the mass
number is 6 + 6 = 12.
Step 3: Determine the symbol of the atom: The symbol of an
element is determined by using the atomic number and the mass
number. The symbol is written as follows:
Symbol =element’s symbol −atomic number −mass number
In this case, the element is carbon with an atomic number of 6 and
a mass number of 12. Therefore, the symbol of the atom is:
Symbol =C−6−12
Symbol =12
6C
Thus, the atomic number is 6, the mass number is 12, and the
symbol of the atom is 12
6C.
Question 10
Step-by-step solution: 1. An atom is the smallest unit of mat-
ter that retains the properties of an element, consisting of a nucleus
containing positively charged protons and uncharged neutrons, sur-
rounded by negatively charged electrons. 2. A molecule is a group of
two or more atoms bonded together, representing the smallest unit of
a compound that retains the chemical properties of that compound.
3. Atoms of different elements combine to form molecules through
chemical bonding, while atoms of the same element can also bond to
form molecules. 4. The properties of an atom depend on the number
of protons, neutrons, and electrons it contains, while the properties
of a molecule depend on the types and arrangement of atoms within
7
it. 5. Atoms can exist independently or combine with other atoms to
form molecules, while molecules cannot exist independently and are
always composed of two or more atoms bonded together.Question 10:
Describe the differences between an atom and a molecule.
Step-by-step solution: 1. An atom is the smallest unit of mat-
ter that retains the properties of an element, consisting of a nucleus
containing positively charged protons and uncharged neutrons, sur-
rounded by negatively charged electrons. 2. A molecule is a group of
two or more atoms bonded together, representing the smallest unit of
a compound that retains the chemical properties of that compound.
3. Atoms of different elements combine to form molecules through
chemical bonding, while atoms of the same element can also bond to
form molecules. 4. The properties of an atom depend on the number
of protons, neutrons, and electrons it contains, while the properties
of a molecule depend on the types and arrangement of atoms within
it. 5. Atoms can exist independently or combine with other atoms to
form molecules, while molecules cannot exist independently and are
always composed of two or more atoms bonded together.
8
Step-by-step solutions: a) The atomic number of an element rep-
resents the number of protons in its nucleus. Therefore, this element
with an atomic number of 20 has 20 protons.
b) For an electrically neutral atom, the number of protons in the
nucleus must be equal to the number of electrons surrounding the
nucleus. Hence, this element with 20 protons will also have 20 elec-
trons.
c) The symbol of an element is derived from its name or Latin
name. For the element with 20 protons (atomic number), the symbol
is Ca which represents Calcium.Question 2:
A certain element has an atomic number of 20.
a) How many protons does this element have? b) How many elec-
trons does this element have if it is electrically neutral? c) What is
the symbol of this element?
Step-by-step solutions: a) The atomic number of an element rep-
resents the number of protons in its nucleus. Therefore, this element
with an atomic number of 20 has 20 protons.
b) For an electrically neutral atom, the number of protons in the
nucleus must be equal to the number of electrons surrounding the
nucleus. Hence, this element with 20 protons will also have 20 elec-
trons.
c) The symbol of an element is derived from its name or Latin
name. For the element with 20 protons (atomic number), the symbol
is Ca which represents Calcium.
Question 3
Step-by-step solutions: a) Since the atom is neutral, the number
of protons in the nucleus must be equal to the number of electrons
surrounding the nucleus. Therefore, the atom has 18 protons.
b) The atomic number of an element is equal to the number of
protons in the nucleus. So, the atomic number of this atom is also
18.
c) To determine the number of electrons in the outermost energy
level (valence electrons), you can refer to the periodic table and find
the group number of the element with an atomic number of 18. In
this case, element number 18 is in group 18 of the periodic table,
which means it has 8 valence electrons.Question 3: Given a neutral
atom with 18 electrons, answer the following questions: a) How many
protons are in the nucleus of this atom? b) What is the atomic
number of this atom? c) How many electrons are in the outermost
energy level of this atom?
Step-by-step solutions: a) Since the atom is neutral, the number
of protons in the nucleus must be equal to the number of electrons
surrounding the nucleus. Therefore, the atom has 18 protons.
2
b) The atomic number of an element is equal to the number of
protons in the nucleus. So, the atomic number of this atom is also
18.
c) To determine the number of electrons in the outermost energy
level (valence electrons), you can refer to the periodic table and find
the group number of the element with an atomic number of 18. In
this case, element number 18 is in group 18 of the periodic table,
which means it has 8 valence electrons.
Question 4
Step-by-step solution: 1. The atomic number (Z) of an element
represents the number of protons in the nucleus. 2. The atomic
number of the element is given as 8. Therefore, the number of protons
(P) in the nucleus is 8. 3. The number of electrons in a neutral atom
is equal to the number of protons. So, the number of electrons (E)
is also 8. 4. To determine the number of neutrons (N), you need
to use the mass number formula: Mass number (A) = Number of
protons (P) + Number of neutrons (N). 5. If the atom is neutral,
the number of protons equals the number of electrons, which means
the charge is balanced. 6. Since the element is not specified, the
exact mass number is unknown. Therefore, you typically assume a
standard atomic weight for oxygen. 7. Oxygen usually has a standard
atomic weight of approximately 16. This means the mass number of
this oxygen atom would be approximately 16. 8. Using the mass
number formula, 16 = 8 protons + Number of neutrons. 9. Solving
for the number of neutrons: Number of neutrons = 16 - 8 = 8. 10.
Therefore, the atom of the element with atomic number 8 contains
8 protons, 8 electrons, and 8 neutrons.Question 4: An element has
an atomic number of 8. Determine the number of protons, electrons,
and neutrons in an atom of this element.
Step-by-step solution: 1. The atomic number (Z) of an element
represents the number of protons in the nucleus. 2. The atomic
number of the element is given as 8. Therefore, the number of protons
(P) in the nucleus is 8. 3. The number of electrons in a neutral atom
is equal to the number of protons. So, the number of electrons (E)
is also 8. 4. To determine the number of neutrons (N), you need
to use the mass number formula: Mass number (A) = Number of
protons (P) + Number of neutrons (N). 5. If the atom is neutral,
the number of protons equals the number of electrons, which means
the charge is balanced. 6. Since the element is not specified, the
exact mass number is unknown. Therefore, you typically assume a
standard atomic weight for oxygen. 7. Oxygen usually has a standard
atomic weight of approximately 16. This means the mass number of
this oxygen atom would be approximately 16. 8. Using the mass
3
number formula, 16 = 8 protons + Number of neutrons. 9. Solving
for the number of neutrons: Number of neutrons = 16 - 8 = 8. 10.
Therefore, the atom of the element with atomic number 8 contains 8
protons, 8 electrons, and 8 neutrons.
Question 5
Step 1: Identify the atomic number and mass number of the car-
bon atom. - The atomic number of carbon is 6, which indicates the
number of protons. - The mass number is the sum of protons and
neutrons, which is 6 protons + 6 neutrons = 12.
Step 2: Atomic mass calculation. - The atomic mass is the weighted
average of all naturally occurring isotopes of an element. - Since
carbon has several isotopes, we need to consider their relative abun-
dances to calculate the atomic mass. - The most abundant isotope of
carbon is carbon-12 with an abundance of 98.89
Step 3: Calculate the atomic mass of carbon. - To calculate the
atomic mass, multiply the abundance of each isotope by its mass
number, then sum the results. - Atomic mass = (0.9889 * 12) +
(0.0111 * 13) - Atomic mass = 11.8668 + 0.1443 - Atomic mass 12.01
Therefore, the atomic mass of the carbon atom with 6 protons and
6 neutrons is approximately 12.01.Question 5: An atom of carbon has
6 protons and 6 neutrons. Calculate the atomic mass of this carbon
atom.
Step 1: Identify the atomic number and mass number of the car-
bon atom. - The atomic number of carbon is 6, which indicates the
number of protons. - The mass number is the sum of protons and
neutrons, which is 6 protons + 6 neutrons = 12.
Step 2: Atomic mass calculation. - The atomic mass is the weighted
average of all naturally occurring isotopes of an element. - Since
carbon has several isotopes, we need to consider their relative abun-
dances to calculate the atomic mass. - The most abundant isotope of
carbon is carbon-12 with an abundance of 98.89
Step 3: Calculate the atomic mass of carbon. - To calculate the
atomic mass, multiply the abundance of each isotope by its mass
number, then sum the results. - Atomic mass = (0.9889 * 12) +
(0.0111 * 13) - Atomic mass = 11.8668 + 0.1443 - Atomic mass 12.01
Therefore, the atomic mass of the carbon atom with 6 protons and
6 neutrons is approximately 12.01.
Question 6
Step-by-step solution: 1. The atomic number of an atom indicates
the number of protons it has. In this case, the carbon atom has 6
4
protons. 2. The number of neutrons in an atom can be calculated by
subtracting the atomic number from the mass number. In this case,
the carbon atom has 6 neutrons. 3. The mass number of an atom is
the sum of its protons and neutrons. Therefore, the mass number of
the carbon atom is 6 (protons) + 6 (neutrons) = 12. 4. The number
of electrons in a neutral atom is equal to the number of protons. Since
the carbon atom has 6 protons, it also has 6 electrons.Question 6: A
carbon atom has 6 protons, 6 neutrons, and 6 electrons.
Step-by-step solution: 1. The atomic number of an atom indicates
the number of protons it has. In this case, the carbon atom has 6
protons. 2. The number of neutrons in an atom can be calculated
by subtracting the atomic number from the mass number. In this
case, the carbon atom has 6 neutrons. 3. The mass number of an
atom is the sum of its protons and neutrons. Therefore, the mass
number of the carbon atom is 6 (protons) + 6 (neutrons) = 12. 4.
The number of electrons in a neutral atom is equal to the number of
protons. Since the carbon atom has 6 protons, it also has 6 electrons.
Question 7
Step-by-step solution: 1. The atomic number of an element is
equal to the number of protons in its nucleus. Since the carbon atom
has 6 protons, its atomic number is 6. 2. The mass number of an
element is equal to the sum of the number of protons and neutrons
in its nucleus. In this case, the carbon atom has 6 protons and 6
neutrons, so its mass number is 6 + 6 = 12. 3. The number of
protons in an atom is always equal to its atomic number. Therefore,
the carbon atom has 6 protons. 4. The number of neutrons in an
atom is equal to the mass number minus the atomic number. So, the
carbon atom has 12 - 6 = 6 neutrons. 5. The number of electrons in
a neutral atom is equal to the number of protons. Since the carbon
atom has 6 protons, it also has 6 electrons.Question 7: A carbon
atom has 6 protons, 6 neutrons, and 6 electrons. Determine the
atomic number, mass number, and the number of protons, neutrons,
and electrons in this carbon atom.
Step-by-step solution: 1. The atomic number of an element is
equal to the number of protons in its nucleus. Since the carbon atom
has 6 protons, its atomic number is 6. 2. The mass number of an
element is equal to the sum of the number of protons and neutrons
in its nucleus. In this case, the carbon atom has 6 protons and 6
neutrons, so its mass number is 6 + 6 = 12. 3. The number of
protons in an atom is always equal to its atomic number. Therefore,
the carbon atom has 6 protons. 4. The number of neutrons in an
atom is equal to the mass number minus the atomic number. So, the
carbon atom has 12 - 6 = 6 neutrons. 5. The number of electrons in
5
a neutral atom is equal to the number of protons. Since the carbon
atom has 6 protons, it also has 6 electrons.
Question 8
Step 1: Identify the atomic number and mass number - Atomic
number (Z) = 20 - Mass number (A) = 40
Step 2: Determine the number of protons (p+) - The number of
protons is equal to the atomic number p+ = Z p+ = 20
Step 3: Find the number of neutrons (n0) - Neutrons can be cal-
culated by subtracting the number of protons from the mass number
n0 = A - p+ n0 = 40 - 20 n0 = 20
Step 4: Calculate the number of electrons (e-) - For a neutral
atom, the number of electrons is equal to the number of protons e-
= p+ e- = 20
Answer: The atom has: - 20 protons - 20 neutrons - 20 electron-
sQuestion 8: Calculate the number of protons, neutrons, and elec-
trons in an atom with the following information: - Atomic number =
20 - Mass number = 40
Step 1: Identify the atomic number and mass number - Atomic
number (Z) = 20 - Mass number (A) = 40
Step 2: Determine the number of protons (p+) - The number of
protons is equal to the atomic number p+ = Z p+ = 20
Step 3: Find the number of neutrons (n0) - Neutrons can be cal-
culated by subtracting the number of protons from the mass number
n0 = A - p+ n0 = 40 - 20 n0 = 20
Step 4: Calculate the number of electrons (e-) - For a neutral
atom, the number of electrons is equal to the number of protons e-
= p+ e- = 20
Answer: The atom has: - 20 protons - 20 neutrons - 20 electrons
Question 9
Step 1: Determine the atomic number: The atomic number is
equal to the number of protons in an atom. In this case, the atom
has 6 protons. Therefore, the atomic number is 6.
Step 2: Determine the mass number: The mass number is equal
to the sum of the number of protons and neutrons in an atom. In this
case, the atom has 6 protons and 6 neutrons. Therefore, the mass
number is 6 + 6 = 12.
Step 3: Determine the symbol of the atom: The symbol of an
element is determined by using the atomic number and the mass
number. The symbol is written as follows:
Symbol =element’s symbol −atomic number −mass number
6
In this case, the element is carbon with an atomic number of 6 and
a mass number of 12. Therefore, the symbol of the atom is:
Symbol =C−6−12
Symbol =12
6C
Thus, the atomic number is 6, the mass number is 12, and the
symbol of the atom is 12
6C.Question 9: An atom has 6 protons, 6 neu-
trons, and 6 electrons. Determine the atomic number, mass number,
and the symbol of the atom.
Step 1: Determine the atomic number: The atomic number is
equal to the number of protons in an atom. In this case, the atom
has 6 protons. Therefore, the atomic number is 6.
Step 2: Determine the mass number: The mass number is equal
to the sum of the number of protons and neutrons in an atom. In this
case, the atom has 6 protons and 6 neutrons. Therefore, the mass
number is 6 + 6 = 12.
Step 3: Determine the symbol of the atom: The symbol of an
element is determined by using the atomic number and the mass
number. The symbol is written as follows:
Symbol =element’s symbol −atomic number −mass number
In this case, the element is carbon with an atomic number of 6 and
a mass number of 12. Therefore, the symbol of the atom is:
Symbol =C−6−12
Symbol =12
6C
Thus, the atomic number is 6, the mass number is 12, and the
symbol of the atom is 12
6C.
Question 10
Step-by-step solution: 1. An atom is the smallest unit of mat-
ter that retains the properties of an element, consisting of a nucleus
containing positively charged protons and uncharged neutrons, sur-
rounded by negatively charged electrons. 2. A molecule is a group of
two or more atoms bonded together, representing the smallest unit of
a compound that retains the chemical properties of that compound.
3. Atoms of different elements combine to form molecules through
chemical bonding, while atoms of the same element can also bond to
form molecules. 4. The properties of an atom depend on the number
of protons, neutrons, and electrons it contains, while the properties
of a molecule depend on the types and arrangement of atoms within
7
it. 5. Atoms can exist independently or combine with other atoms to
form molecules, while molecules cannot exist independently and are
always composed of two or more atoms bonded together.Question 10:
Describe the differences between an atom and a molecule.
Step-by-step solution: 1. An atom is the smallest unit of mat-
ter that retains the properties of an element, consisting of a nucleus
containing positively charged protons and uncharged neutrons, sur-
rounded by negatively charged electrons. 2. A molecule is a group of
two or more atoms bonded together, representing the smallest unit of
a compound that retains the chemical properties of that compound.
3. Atoms of different elements combine to form molecules through
chemical bonding, while atoms of the same element can also bond to
form molecules. 4. The properties of an atom depend on the number
of protons, neutrons, and electrons it contains, while the properties
of a molecule depend on the types and arrangement of atoms within
it. 5. Atoms can exist independently or combine with other atoms to
form molecules, while molecules cannot exist independently and are
always composed of two or more atoms bonded together.
8
Step-by-step solutions: a) The atomic number of an element rep-
resents the number of protons in its nucleus. Therefore, this element
with an atomic number of 20 has 20 protons.
b) For an electrically neutral atom, the number of protons in the
nucleus must be equal to the number of electrons surrounding the
nucleus. Hence, this element with 20 protons will also have 20 elec-
trons.
c) The symbol of an element is derived from its name or Latin
name. For the element with 20 protons (atomic number), the symbol
is Ca which represents Calcium.Question 2:
A certain element has an atomic number of 20.
a) How many protons does this element have? b) How many elec-
trons does this element have if it is electrically neutral? c) What is
the symbol of this element?
Step-by-step solutions: a) The atomic number of an element rep-
resents the number of protons in its nucleus. Therefore, this element
with an atomic number of 20 has 20 protons.
b) For an electrically neutral atom, the number of protons in the
nucleus must be equal to the number of electrons surrounding the
nucleus. Hence, this element with 20 protons will also have 20 elec-
trons.
c) The symbol of an element is derived from its name or Latin
name. For the element with 20 protons (atomic number), the symbol
is Ca which represents Calcium.
Question 3
Step-by-step solutions: a) Since the atom is neutral, the number
of protons in the nucleus must be equal to the number of electrons
surrounding the nucleus. Therefore, the atom has 18 protons.
b) The atomic number of an element is equal to the number of
protons in the nucleus. So, the atomic number of this atom is also
18.
c) To determine the number of electrons in the outermost energy
level (valence electrons), you can refer to the periodic table and find
the group number of the element with an atomic number of 18. In
this case, element number 18 is in group 18 of the periodic table,
which means it has 8 valence electrons.Question 3: Given a neutral
atom with 18 electrons, answer the following questions: a) How many
protons are in the nucleus of this atom? b) What is the atomic
number of this atom? c) How many electrons are in the outermost
energy level of this atom?
Step-by-step solutions: a) Since the atom is neutral, the number
of protons in the nucleus must be equal to the number of electrons
surrounding the nucleus. Therefore, the atom has 18 protons.
2
b) The atomic number of an element is equal to the number of
protons in the nucleus. So, the atomic number of this atom is also
18.
c) To determine the number of electrons in the outermost energy
level (valence electrons), you can refer to the periodic table and find
the group number of the element with an atomic number of 18. In
this case, element number 18 is in group 18 of the periodic table,
which means it has 8 valence electrons.
Question 4
Step-by-step solution: 1. The atomic number (Z) of an element
represents the number of protons in the nucleus. 2. The atomic
number of the element is given as 8. Therefore, the number of protons
(P) in the nucleus is 8. 3. The number of electrons in a neutral atom
is equal to the number of protons. So, the number of electrons (E)
is also 8. 4. To determine the number of neutrons (N), you need
to use the mass number formula: Mass number (A) = Number of
protons (P) + Number of neutrons (N). 5. If the atom is neutral,
the number of protons equals the number of electrons, which means
the charge is balanced. 6. Since the element is not specified, the
exact mass number is unknown. Therefore, you typically assume a
standard atomic weight for oxygen. 7. Oxygen usually has a standard
atomic weight of approximately 16. This means the mass number of
this oxygen atom would be approximately 16. 8. Using the mass
number formula, 16 = 8 protons + Number of neutrons. 9. Solving
for the number of neutrons: Number of neutrons = 16 - 8 = 8. 10.
Therefore, the atom of the element with atomic number 8 contains
8 protons, 8 electrons, and 8 neutrons.Question 4: An element has
an atomic number of 8. Determine the number of protons, electrons,
and neutrons in an atom of this element.
Step-by-step solution: 1. The atomic number (Z) of an element
represents the number of protons in the nucleus. 2. The atomic
number of the element is given as 8. Therefore, the number of protons
(P) in the nucleus is 8. 3. The number of electrons in a neutral atom
is equal to the number of protons. So, the number of electrons (E)
is also 8. 4. To determine the number of neutrons (N), you need
to use the mass number formula: Mass number (A) = Number of
protons (P) + Number of neutrons (N). 5. If the atom is neutral,
the number of protons equals the number of electrons, which means
the charge is balanced. 6. Since the element is not specified, the
exact mass number is unknown. Therefore, you typically assume a
standard atomic weight for oxygen. 7. Oxygen usually has a standard
atomic weight of approximately 16. This means the mass number of
this oxygen atom would be approximately 16. 8. Using the mass
3
number formula, 16 = 8 protons + Number of neutrons. 9. Solving
for the number of neutrons: Number of neutrons = 16 - 8 = 8. 10.
Therefore, the atom of the element with atomic number 8 contains 8
protons, 8 electrons, and 8 neutrons.
Question 5
Step 1: Identify the atomic number and mass number of the car-
bon atom. - The atomic number of carbon is 6, which indicates the
number of protons. - The mass number is the sum of protons and
neutrons, which is 6 protons + 6 neutrons = 12.
Step 2: Atomic mass calculation. - The atomic mass is the weighted
average of all naturally occurring isotopes of an element. - Since
carbon has several isotopes, we need to consider their relative abun-
dances to calculate the atomic mass. - The most abundant isotope of
carbon is carbon-12 with an abundance of 98.89
Step 3: Calculate the atomic mass of carbon. - To calculate the
atomic mass, multiply the abundance of each isotope by its mass
number, then sum the results. - Atomic mass = (0.9889 * 12) +
(0.0111 * 13) - Atomic mass = 11.8668 + 0.1443 - Atomic mass 12.01
Therefore, the atomic mass of the carbon atom with 6 protons and
6 neutrons is approximately 12.01.Question 5: An atom of carbon has
6 protons and 6 neutrons. Calculate the atomic mass of this carbon
atom.
Step 1: Identify the atomic number and mass number of the car-
bon atom. - The atomic number of carbon is 6, which indicates the
number of protons. - The mass number is the sum of protons and
neutrons, which is 6 protons + 6 neutrons = 12.
Step 2: Atomic mass calculation. - The atomic mass is the weighted
average of all naturally occurring isotopes of an element. - Since
carbon has several isotopes, we need to consider their relative abun-
dances to calculate the atomic mass. - The most abundant isotope of
carbon is carbon-12 with an abundance of 98.89
Step 3: Calculate the atomic mass of carbon. - To calculate the
atomic mass, multiply the abundance of each isotope by its mass
number, then sum the results. - Atomic mass = (0.9889 * 12) +
(0.0111 * 13) - Atomic mass = 11.8668 + 0.1443 - Atomic mass 12.01
Therefore, the atomic mass of the carbon atom with 6 protons and
6 neutrons is approximately 12.01.
Question 6
Step-by-step solution: 1. The atomic number of an atom indicates
the number of protons it has. In this case, the carbon atom has 6
4
protons. 2. The number of neutrons in an atom can be calculated by
subtracting the atomic number from the mass number. In this case,
the carbon atom has 6 neutrons. 3. The mass number of an atom is
the sum of its protons and neutrons. Therefore, the mass number of
the carbon atom is 6 (protons) + 6 (neutrons) = 12. 4. The number
of electrons in a neutral atom is equal to the number of protons. Since
the carbon atom has 6 protons, it also has 6 electrons.Question 6: A
carbon atom has 6 protons, 6 neutrons, and 6 electrons.
Step-by-step solution: 1. The atomic number of an atom indicates
the number of protons it has. In this case, the carbon atom has 6
protons. 2. The number of neutrons in an atom can be calculated
by subtracting the atomic number from the mass number. In this
case, the carbon atom has 6 neutrons. 3. The mass number of an
atom is the sum of its protons and neutrons. Therefore, the mass
number of the carbon atom is 6 (protons) + 6 (neutrons) = 12. 4.
The number of electrons in a neutral atom is equal to the number of
protons. Since the carbon atom has 6 protons, it also has 6 electrons.
Question 7
Step-by-step solution: 1. The atomic number of an element is
equal to the number of protons in its nucleus. Since the carbon atom
has 6 protons, its atomic number is 6. 2. The mass number of an
element is equal to the sum of the number of protons and neutrons
in its nucleus. In this case, the carbon atom has 6 protons and 6
neutrons, so its mass number is 6 + 6 = 12. 3. The number of
protons in an atom is always equal to its atomic number. Therefore,
the carbon atom has 6 protons. 4. The number of neutrons in an
atom is equal to the mass number minus the atomic number. So, the
carbon atom has 12 - 6 = 6 neutrons. 5. The number of electrons in
a neutral atom is equal to the number of protons. Since the carbon
atom has 6 protons, it also has 6 electrons.Question 7: A carbon
atom has 6 protons, 6 neutrons, and 6 electrons. Determine the
atomic number, mass number, and the number of protons, neutrons,
and electrons in this carbon atom.
Step-by-step solution: 1. The atomic number of an element is
equal to the number of protons in its nucleus. Since the carbon atom
has 6 protons, its atomic number is 6. 2. The mass number of an
element is equal to the sum of the number of protons and neutrons
in its nucleus. In this case, the carbon atom has 6 protons and 6
neutrons, so its mass number is 6 + 6 = 12. 3. The number of
protons in an atom is always equal to its atomic number. Therefore,
the carbon atom has 6 protons. 4. The number of neutrons in an
atom is equal to the mass number minus the atomic number. So, the
carbon atom has 12 - 6 = 6 neutrons. 5. The number of electrons in
5
a neutral atom is equal to the number of protons. Since the carbon
atom has 6 protons, it also has 6 electrons.
Question 8
Step 1: Identify the atomic number and mass number - Atomic
number (Z) = 20 - Mass number (A) = 40
Step 2: Determine the number of protons (p+) - The number of
protons is equal to the atomic number p+ = Z p+ = 20
Step 3: Find the number of neutrons (n0) - Neutrons can be cal-
culated by subtracting the number of protons from the mass number
n0 = A - p+ n0 = 40 - 20 n0 = 20
Step 4: Calculate the number of electrons (e-) - For a neutral
atom, the number of electrons is equal to the number of protons e-
= p+ e- = 20
Answer: The atom has: - 20 protons - 20 neutrons - 20 electron-
sQuestion 8: Calculate the number of protons, neutrons, and elec-
trons in an atom with the following information: - Atomic number =
20 - Mass number = 40
Step 1: Identify the atomic number and mass number - Atomic
number (Z) = 20 - Mass number (A) = 40
Step 2: Determine the number of protons (p+) - The number of
protons is equal to the atomic number p+ = Z p+ = 20
Step 3: Find the number of neutrons (n0) - Neutrons can be cal-
culated by subtracting the number of protons from the mass number
n0 = A - p+ n0 = 40 - 20 n0 = 20
Step 4: Calculate the number of electrons (e-) - For a neutral
atom, the number of electrons is equal to the number of protons e-
= p+ e- = 20
Answer: The atom has: - 20 protons - 20 neutrons - 20 electrons
Question 9
Step 1: Determine the atomic number: The atomic number is
equal to the number of protons in an atom. In this case, the atom
has 6 protons. Therefore, the atomic number is 6.
Step 2: Determine the mass number: The mass number is equal
to the sum of the number of protons and neutrons in an atom. In this
case, the atom has 6 protons and 6 neutrons. Therefore, the mass
number is 6 + 6 = 12.
Step 3: Determine the symbol of the atom: The symbol of an
element is determined by using the atomic number and the mass
number. The symbol is written as follows:
Symbol =element’s symbol −atomic number −mass number
6
In this case, the element is carbon with an atomic number of 6 and
a mass number of 12. Therefore, the symbol of the atom is:
Symbol =C−6−12
Symbol =12
6C
Thus, the atomic number is 6, the mass number is 12, and the
symbol of the atom is 12
6C.Question 9: An atom has 6 protons, 6 neu-
trons, and 6 electrons. Determine the atomic number, mass number,
and the symbol of the atom.
Step 1: Determine the atomic number: The atomic number is
equal to the number of protons in an atom. In this case, the atom
has 6 protons. Therefore, the atomic number is 6.
Step 2: Determine the mass number: The mass number is equal
to the sum of the number of protons and neutrons in an atom. In this
case, the atom has 6 protons and 6 neutrons. Therefore, the mass
number is 6 + 6 = 12.
Step 3: Determine the symbol of the atom: The symbol of an
element is determined by using the atomic number and the mass
number. The symbol is written as follows:
Symbol =element’s symbol −atomic number −mass number
In this case, the element is carbon with an atomic number of 6 and
a mass number of 12. Therefore, the symbol of the atom is:
Symbol =C−6−12
Symbol =12
6C
Thus, the atomic number is 6, the mass number is 12, and the
symbol of the atom is 12
6C.
Question 10
Step-by-step solution: 1. An atom is the smallest unit of mat-
ter that retains the properties of an element, consisting of a nucleus
containing positively charged protons and uncharged neutrons, sur-
rounded by negatively charged electrons. 2. A molecule is a group of
two or more atoms bonded together, representing the smallest unit of
a compound that retains the chemical properties of that compound.
3. Atoms of different elements combine to form molecules through
chemical bonding, while atoms of the same element can also bond to
form molecules. 4. The properties of an atom depend on the number
of protons, neutrons, and electrons it contains, while the properties
of a molecule depend on the types and arrangement of atoms within
7
it. 5. Atoms can exist independently or combine with other atoms to
form molecules, while molecules cannot exist independently and are
always composed of two or more atoms bonded together.Question 10:
Describe the differences between an atom and a molecule.
Step-by-step solution: 1. An atom is the smallest unit of mat-
ter that retains the properties of an element, consisting of a nucleus
containing positively charged protons and uncharged neutrons, sur-
rounded by negatively charged electrons. 2. A molecule is a group of
two or more atoms bonded together, representing the smallest unit of
a compound that retains the chemical properties of that compound.
3. Atoms of different elements combine to form molecules through
chemical bonding, while atoms of the same element can also bond to
form molecules. 4. The properties of an atom depend on the number
of protons, neutrons, and electrons it contains, while the properties
of a molecule depend on the types and arrangement of atoms within
it. 5. Atoms can exist independently or combine with other atoms to
form molecules, while molecules cannot exist independently and are
always composed of two or more atoms bonded together.
8
Step-by-step solutions: a) The atomic number of an element rep-
resents the number of protons in its nucleus. Therefore, this element
with an atomic number of 20 has 20 protons.
b) For an electrically neutral atom, the number of protons in the
nucleus must be equal to the number of electrons surrounding the
nucleus. Hence, this element with 20 protons will also have 20 elec-
trons.
c) The symbol of an element is derived from its name or Latin
name. For the element with 20 protons (atomic number), the symbol
is Ca which represents Calcium.Question 2:
A certain element has an atomic number of 20.
a) How many protons does this element have? b) How many elec-
trons does this element have if it is electrically neutral? c) What is
the symbol of this element?
Step-by-step solutions: a) The atomic number of an element rep-
resents the number of protons in its nucleus. Therefore, this element
with an atomic number of 20 has 20 protons.
b) For an electrically neutral atom, the number of protons in the
nucleus must be equal to the number of electrons surrounding the
nucleus. Hence, this element with 20 protons will also have 20 elec-
trons.
c) The symbol of an element is derived from its name or Latin
name. For the element with 20 protons (atomic number), the symbol
is Ca which represents Calcium.
Question 3
Step-by-step solutions: a) Since the atom is neutral, the number
of protons in the nucleus must be equal to the number of electrons
surrounding the nucleus. Therefore, the atom has 18 protons.
b) The atomic number of an element is equal to the number of
protons in the nucleus. So, the atomic number of this atom is also
18.
c) To determine the number of electrons in the outermost energy
level (valence electrons), you can refer to the periodic table and find
the group number of the element with an atomic number of 18. In
this case, element number 18 is in group 18 of the periodic table,
which means it has 8 valence electrons.Question 3: Given a neutral
atom with 18 electrons, answer the following questions: a) How many
protons are in the nucleus of this atom? b) What is the atomic
number of this atom? c) How many electrons are in the outermost
energy level of this atom?
Step-by-step solutions: a) Since the atom is neutral, the number
of protons in the nucleus must be equal to the number of electrons
surrounding the nucleus. Therefore, the atom has 18 protons.
2
b) The atomic number of an element is equal to the number of
protons in the nucleus. So, the atomic number of this atom is also
18.
c) To determine the number of electrons in the outermost energy
level (valence electrons), you can refer to the periodic table and find
the group number of the element with an atomic number of 18. In
this case, element number 18 is in group 18 of the periodic table,
which means it has 8 valence electrons.
Question 4
Step-by-step solution: 1. The atomic number (Z) of an element
represents the number of protons in the nucleus. 2. The atomic
number of the element is given as 8. Therefore, the number of protons
(P) in the nucleus is 8. 3. The number of electrons in a neutral atom
is equal to the number of protons. So, the number of electrons (E)
is also 8. 4. To determine the number of neutrons (N), you need
to use the mass number formula: Mass number (A) = Number of
protons (P) + Number of neutrons (N). 5. If the atom is neutral,
the number of protons equals the number of electrons, which means
the charge is balanced. 6. Since the element is not specified, the
exact mass number is unknown. Therefore, you typically assume a
standard atomic weight for oxygen. 7. Oxygen usually has a standard
atomic weight of approximately 16. This means the mass number of
this oxygen atom would be approximately 16. 8. Using the mass
number formula, 16 = 8 protons + Number of neutrons. 9. Solving
for the number of neutrons: Number of neutrons = 16 - 8 = 8. 10.
Therefore, the atom of the element with atomic number 8 contains
8 protons, 8 electrons, and 8 neutrons.Question 4: An element has
an atomic number of 8. Determine the number of protons, electrons,
and neutrons in an atom of this element.
Step-by-step solution: 1. The atomic number (Z) of an element
represents the number of protons in the nucleus. 2. The atomic
number of the element is given as 8. Therefore, the number of protons
(P) in the nucleus is 8. 3. The number of electrons in a neutral atom
is equal to the number of protons. So, the number of electrons (E)
is also 8. 4. To determine the number of neutrons (N), you need
to use the mass number formula: Mass number (A) = Number of
protons (P) + Number of neutrons (N). 5. If the atom is neutral,
the number of protons equals the number of electrons, which means
the charge is balanced. 6. Since the element is not specified, the
exact mass number is unknown. Therefore, you typically assume a
standard atomic weight for oxygen. 7. Oxygen usually has a standard
atomic weight of approximately 16. This means the mass number of
this oxygen atom would be approximately 16. 8. Using the mass
3
number formula, 16 = 8 protons + Number of neutrons. 9. Solving
for the number of neutrons: Number of neutrons = 16 - 8 = 8. 10.
Therefore, the atom of the element with atomic number 8 contains 8
protons, 8 electrons, and 8 neutrons.
Question 5
Step 1: Identify the atomic number and mass number of the car-
bon atom. - The atomic number of carbon is 6, which indicates the
number of protons. - The mass number is the sum of protons and
neutrons, which is 6 protons + 6 neutrons = 12.
Step 2: Atomic mass calculation. - The atomic mass is the weighted
average of all naturally occurring isotopes of an element. - Since
carbon has several isotopes, we need to consider their relative abun-
dances to calculate the atomic mass. - The most abundant isotope of
carbon is carbon-12 with an abundance of 98.89
Step 3: Calculate the atomic mass of carbon. - To calculate the
atomic mass, multiply the abundance of each isotope by its mass
number, then sum the results. - Atomic mass = (0.9889 * 12) +
(0.0111 * 13) - Atomic mass = 11.8668 + 0.1443 - Atomic mass 12.01
Therefore, the atomic mass of the carbon atom with 6 protons and
6 neutrons is approximately 12.01.Question 5: An atom of carbon has
6 protons and 6 neutrons. Calculate the atomic mass of this carbon
atom.
Step 1: Identify the atomic number and mass number of the car-
bon atom. - The atomic number of carbon is 6, which indicates the
number of protons. - The mass number is the sum of protons and
neutrons, which is 6 protons + 6 neutrons = 12.
Step 2: Atomic mass calculation. - The atomic mass is the weighted
average of all naturally occurring isotopes of an element. - Since
carbon has several isotopes, we need to consider their relative abun-
dances to calculate the atomic mass. - The most abundant isotope of
carbon is carbon-12 with an abundance of 98.89
Step 3: Calculate the atomic mass of carbon. - To calculate the
atomic mass, multiply the abundance of each isotope by its mass
number, then sum the results. - Atomic mass = (0.9889 * 12) +
(0.0111 * 13) - Atomic mass = 11.8668 + 0.1443 - Atomic mass 12.01
Therefore, the atomic mass of the carbon atom with 6 protons and
6 neutrons is approximately 12.01.
Question 6
Step-by-step solution: 1. The atomic number of an atom indicates
the number of protons it has. In this case, the carbon atom has 6
4
protons. 2. The number of neutrons in an atom can be calculated by
subtracting the atomic number from the mass number. In this case,
the carbon atom has 6 neutrons. 3. The mass number of an atom is
the sum of its protons and neutrons. Therefore, the mass number of
the carbon atom is 6 (protons) + 6 (neutrons) = 12. 4. The number
of electrons in a neutral atom is equal to the number of protons. Since
the carbon atom has 6 protons, it also has 6 electrons.Question 6: A
carbon atom has 6 protons, 6 neutrons, and 6 electrons.
Step-by-step solution: 1. The atomic number of an atom indicates
the number of protons it has. In this case, the carbon atom has 6
protons. 2. The number of neutrons in an atom can be calculated
by subtracting the atomic number from the mass number. In this
case, the carbon atom has 6 neutrons. 3. The mass number of an
atom is the sum of its protons and neutrons. Therefore, the mass
number of the carbon atom is 6 (protons) + 6 (neutrons) = 12. 4.
The number of electrons in a neutral atom is equal to the number of
protons. Since the carbon atom has 6 protons, it also has 6 electrons.
Question 7
Step-by-step solution: 1. The atomic number of an element is
equal to the number of protons in its nucleus. Since the carbon atom
has 6 protons, its atomic number is 6. 2. The mass number of an
element is equal to the sum of the number of protons and neutrons
in its nucleus. In this case, the carbon atom has 6 protons and 6
neutrons, so its mass number is 6 + 6 = 12. 3. The number of
protons in an atom is always equal to its atomic number. Therefore,
the carbon atom has 6 protons. 4. The number of neutrons in an
atom is equal to the mass number minus the atomic number. So, the
carbon atom has 12 - 6 = 6 neutrons. 5. The number of electrons in
a neutral atom is equal to the number of protons. Since the carbon
atom has 6 protons, it also has 6 electrons.Question 7: A carbon
atom has 6 protons, 6 neutrons, and 6 electrons. Determine the
atomic number, mass number, and the number of protons, neutrons,
and electrons in this carbon atom.
Step-by-step solution: 1. The atomic number of an element is
equal to the number of protons in its nucleus. Since the carbon atom
has 6 protons, its atomic number is 6. 2. The mass number of an
element is equal to the sum of the number of protons and neutrons
in its nucleus. In this case, the carbon atom has 6 protons and 6
neutrons, so its mass number is 6 + 6 = 12. 3. The number of
protons in an atom is always equal to its atomic number. Therefore,
the carbon atom has 6 protons. 4. The number of neutrons in an
atom is equal to the mass number minus the atomic number. So, the
carbon atom has 12 - 6 = 6 neutrons. 5. The number of electrons in
5
a neutral atom is equal to the number of protons. Since the carbon
atom has 6 protons, it also has 6 electrons.
Question 8
Step 1: Identify the atomic number and mass number - Atomic
number (Z) = 20 - Mass number (A) = 40
Step 2: Determine the number of protons (p+) - The number of
protons is equal to the atomic number p+ = Z p+ = 20
Step 3: Find the number of neutrons (n0) - Neutrons can be cal-
culated by subtracting the number of protons from the mass number
n0 = A - p+ n0 = 40 - 20 n0 = 20
Step 4: Calculate the number of electrons (e-) - For a neutral
atom, the number of electrons is equal to the number of protons e-
= p+ e- = 20
Answer: The atom has: - 20 protons - 20 neutrons - 20 electron-
sQuestion 8: Calculate the number of protons, neutrons, and elec-
trons in an atom with the following information: - Atomic number =
20 - Mass number = 40
Step 1: Identify the atomic number and mass number - Atomic
number (Z) = 20 - Mass number (A) = 40
Step 2: Determine the number of protons (p+) - The number of
protons is equal to the atomic number p+ = Z p+ = 20
Step 3: Find the number of neutrons (n0) - Neutrons can be cal-
culated by subtracting the number of protons from the mass number
n0 = A - p+ n0 = 40 - 20 n0 = 20
Step 4: Calculate the number of electrons (e-) - For a neutral
atom, the number of electrons is equal to the number of protons e-
= p+ e- = 20
Answer: The atom has: - 20 protons - 20 neutrons - 20 electrons
Question 9
Step 1: Determine the atomic number: The atomic number is
equal to the number of protons in an atom. In this case, the atom
has 6 protons. Therefore, the atomic number is 6.
Step 2: Determine the mass number: The mass number is equal
to the sum of the number of protons and neutrons in an atom. In this
case, the atom has 6 protons and 6 neutrons. Therefore, the mass
number is 6 + 6 = 12.
Step 3: Determine the symbol of the atom: The symbol of an
element is determined by using the atomic number and the mass
number. The symbol is written as follows:
Symbol =element’s symbol −atomic number −mass number
6
In this case, the element is carbon with an atomic number of 6 and
a mass number of 12. Therefore, the symbol of the atom is:
Symbol =C−6−12
Symbol =12
6C
Thus, the atomic number is 6, the mass number is 12, and the
symbol of the atom is 12
6C.Question 9: An atom has 6 protons, 6 neu-
trons, and 6 electrons. Determine the atomic number, mass number,
and the symbol of the atom.
Step 1: Determine the atomic number: The atomic number is
equal to the number of protons in an atom. In this case, the atom
has 6 protons. Therefore, the atomic number is 6.
Step 2: Determine the mass number: The mass number is equal
to the sum of the number of protons and neutrons in an atom. In this
case, the atom has 6 protons and 6 neutrons. Therefore, the mass
number is 6 + 6 = 12.
Step 3: Determine the symbol of the atom: The symbol of an
element is determined by using the atomic number and the mass
number. The symbol is written as follows:
Symbol =element’s symbol −atomic number −mass number
In this case, the element is carbon with an atomic number of 6 and
a mass number of 12. Therefore, the symbol of the atom is:
Symbol =C−6−12
Symbol =12
6C
Thus, the atomic number is 6, the mass number is 12, and the
symbol of the atom is 12
6C.
Question 10
Step-by-step solution: 1. An atom is the smallest unit of mat-
ter that retains the properties of an element, consisting of a nucleus
containing positively charged protons and uncharged neutrons, sur-
rounded by negatively charged electrons. 2. A molecule is a group of
two or more atoms bonded together, representing the smallest unit of
a compound that retains the chemical properties of that compound.
3. Atoms of different elements combine to form molecules through
chemical bonding, while atoms of the same element can also bond to
form molecules. 4. The properties of an atom depend on the number
of protons, neutrons, and electrons it contains, while the properties
of a molecule depend on the types and arrangement of atoms within
7
it. 5. Atoms can exist independently or combine with other atoms to
form molecules, while molecules cannot exist independently and are
always composed of two or more atoms bonded together.Question 10:
Describe the differences between an atom and a molecule.
Step-by-step solution: 1. An atom is the smallest unit of mat-
ter that retains the properties of an element, consisting of a nucleus
containing positively charged protons and uncharged neutrons, sur-
rounded by negatively charged electrons. 2. A molecule is a group of
two or more atoms bonded together, representing the smallest unit of
a compound that retains the chemical properties of that compound.
3. Atoms of different elements combine to form molecules through
chemical bonding, while atoms of the same element can also bond to
form molecules. 4. The properties of an atom depend on the number
of protons, neutrons, and electrons it contains, while the properties
of a molecule depend on the types and arrangement of atoms within
it. 5. Atoms can exist independently or combine with other atoms to
form molecules, while molecules cannot exist independently and are
always composed of two or more atoms bonded together.
8
Step-by-step solutions: a) The atomic number of an element rep-
resents the number of protons in its nucleus. Therefore, this element
with an atomic number of 20 has 20 protons.
b) For an electrically neutral atom, the number of protons in the
nucleus must be equal to the number of electrons surrounding the
nucleus. Hence, this element with 20 protons will also have 20 elec-
trons.
c) The symbol of an element is derived from its name or Latin
name. For the element with 20 protons (atomic number), the symbol
is Ca which represents Calcium.Question 2:
A certain element has an atomic number of 20.
a) How many protons does this element have? b) How many elec-
trons does this element have if it is electrically neutral? c) What is
the symbol of this element?
Step-by-step solutions: a) The atomic number of an element rep-
resents the number of protons in its nucleus. Therefore, this element
with an atomic number of 20 has 20 protons.
b) For an electrically neutral atom, the number of protons in the
nucleus must be equal to the number of electrons surrounding the
nucleus. Hence, this element with 20 protons will also have 20 elec-
trons.
c) The symbol of an element is derived from its name or Latin
name. For the element with 20 protons (atomic number), the symbol
is Ca which represents Calcium.
Question 3
Step-by-step solutions: a) Since the atom is neutral, the number
of protons in the nucleus must be equal to the number of electrons
surrounding the nucleus. Therefore, the atom has 18 protons.
b) The atomic number of an element is equal to the number of
protons in the nucleus. So, the atomic number of this atom is also
18.
c) To determine the number of electrons in the outermost energy
level (valence electrons), you can refer to the periodic table and find
the group number of the element with an atomic number of 18. In
this case, element number 18 is in group 18 of the periodic table,
which means it has 8 valence electrons.Question 3: Given a neutral
atom with 18 electrons, answer the following questions: a) How many
protons are in the nucleus of this atom? b) What is the atomic
number of this atom? c) How many electrons are in the outermost
energy level of this atom?
Step-by-step solutions: a) Since the atom is neutral, the number
of protons in the nucleus must be equal to the number of electrons
surrounding the nucleus. Therefore, the atom has 18 protons.
2
b) The atomic number of an element is equal to the number of
protons in the nucleus. So, the atomic number of this atom is also
18.
c) To determine the number of electrons in the outermost energy
level (valence electrons), you can refer to the periodic table and find
the group number of the element with an atomic number of 18. In
this case, element number 18 is in group 18 of the periodic table,
which means it has 8 valence electrons.
Question 4
Step-by-step solution: 1. The atomic number (Z) of an element
represents the number of protons in the nucleus. 2. The atomic
number of the element is given as 8. Therefore, the number of protons
(P) in the nucleus is 8. 3. The number of electrons in a neutral atom
is equal to the number of protons. So, the number of electrons (E)
is also 8. 4. To determine the number of neutrons (N), you need
to use the mass number formula: Mass number (A) = Number of
protons (P) + Number of neutrons (N). 5. If the atom is neutral,
the number of protons equals the number of electrons, which means
the charge is balanced. 6. Since the element is not specified, the
exact mass number is unknown. Therefore, you typically assume a
standard atomic weight for oxygen. 7. Oxygen usually has a standard
atomic weight of approximately 16. This means the mass number of
this oxygen atom would be approximately 16. 8. Using the mass
number formula, 16 = 8 protons + Number of neutrons. 9. Solving
for the number of neutrons: Number of neutrons = 16 - 8 = 8. 10.
Therefore, the atom of the element with atomic number 8 contains
8 protons, 8 electrons, and 8 neutrons.Question 4: An element has
an atomic number of 8. Determine the number of protons, electrons,
and neutrons in an atom of this element.
Step-by-step solution: 1. The atomic number (Z) of an element
represents the number of protons in the nucleus. 2. The atomic
number of the element is given as 8. Therefore, the number of protons
(P) in the nucleus is 8. 3. The number of electrons in a neutral atom
is equal to the number of protons. So, the number of electrons (E)
is also 8. 4. To determine the number of neutrons (N), you need
to use the mass number formula: Mass number (A) = Number of
protons (P) + Number of neutrons (N). 5. If the atom is neutral,
the number of protons equals the number of electrons, which means
the charge is balanced. 6. Since the element is not specified, the
exact mass number is unknown. Therefore, you typically assume a
standard atomic weight for oxygen. 7. Oxygen usually has a standard
atomic weight of approximately 16. This means the mass number of
this oxygen atom would be approximately 16. 8. Using the mass
3
number formula, 16 = 8 protons + Number of neutrons. 9. Solving
for the number of neutrons: Number of neutrons = 16 - 8 = 8. 10.
Therefore, the atom of the element with atomic number 8 contains 8
protons, 8 electrons, and 8 neutrons.
Question 5
Step 1: Identify the atomic number and mass number of the car-
bon atom. - The atomic number of carbon is 6, which indicates the
number of protons. - The mass number is the sum of protons and
neutrons, which is 6 protons + 6 neutrons = 12.
Step 2: Atomic mass calculation. - The atomic mass is the weighted
average of all naturally occurring isotopes of an element. - Since
carbon has several isotopes, we need to consider their relative abun-
dances to calculate the atomic mass. - The most abundant isotope of
carbon is carbon-12 with an abundance of 98.89
Step 3: Calculate the atomic mass of carbon. - To calculate the
atomic mass, multiply the abundance of each isotope by its mass
number, then sum the results. - Atomic mass = (0.9889 * 12) +
(0.0111 * 13) - Atomic mass = 11.8668 + 0.1443 - Atomic mass 12.01
Therefore, the atomic mass of the carbon atom with 6 protons and
6 neutrons is approximately 12.01.Question 5: An atom of carbon has
6 protons and 6 neutrons. Calculate the atomic mass of this carbon
atom.
Step 1: Identify the atomic number and mass number of the car-
bon atom. - The atomic number of carbon is 6, which indicates the
number of protons. - The mass number is the sum of protons and
neutrons, which is 6 protons + 6 neutrons = 12.
Step 2: Atomic mass calculation. - The atomic mass is the weighted
average of all naturally occurring isotopes of an element. - Since
carbon has several isotopes, we need to consider their relative abun-
dances to calculate the atomic mass. - The most abundant isotope of
carbon is carbon-12 with an abundance of 98.89
Step 3: Calculate the atomic mass of carbon. - To calculate the
atomic mass, multiply the abundance of each isotope by its mass
number, then sum the results. - Atomic mass = (0.9889 * 12) +
(0.0111 * 13) - Atomic mass = 11.8668 + 0.1443 - Atomic mass 12.01
Therefore, the atomic mass of the carbon atom with 6 protons and
6 neutrons is approximately 12.01.
Question 6
Step-by-step solution: 1. The atomic number of an atom indicates
the number of protons it has. In this case, the carbon atom has 6
4
protons. 2. The number of neutrons in an atom can be calculated by
subtracting the atomic number from the mass number. In this case,
the carbon atom has 6 neutrons. 3. The mass number of an atom is
the sum of its protons and neutrons. Therefore, the mass number of
the carbon atom is 6 (protons) + 6 (neutrons) = 12. 4. The number
of electrons in a neutral atom is equal to the number of protons. Since
the carbon atom has 6 protons, it also has 6 electrons.Question 6: A
carbon atom has 6 protons, 6 neutrons, and 6 electrons.
Step-by-step solution: 1. The atomic number of an atom indicates
the number of protons it has. In this case, the carbon atom has 6
protons. 2. The number of neutrons in an atom can be calculated
by subtracting the atomic number from the mass number. In this
case, the carbon atom has 6 neutrons. 3. The mass number of an
atom is the sum of its protons and neutrons. Therefore, the mass
number of the carbon atom is 6 (protons) + 6 (neutrons) = 12. 4.
The number of electrons in a neutral atom is equal to the number of
protons. Since the carbon atom has 6 protons, it also has 6 electrons.
Question 7
Step-by-step solution: 1. The atomic number of an element is
equal to the number of protons in its nucleus. Since the carbon atom
has 6 protons, its atomic number is 6. 2. The mass number of an
element is equal to the sum of the number of protons and neutrons
in its nucleus. In this case, the carbon atom has 6 protons and 6
neutrons, so its mass number is 6 + 6 = 12. 3. The number of
protons in an atom is always equal to its atomic number. Therefore,
the carbon atom has 6 protons. 4. The number of neutrons in an
atom is equal to the mass number minus the atomic number. So, the
carbon atom has 12 - 6 = 6 neutrons. 5. The number of electrons in
a neutral atom is equal to the number of protons. Since the carbon
atom has 6 protons, it also has 6 electrons.Question 7: A carbon
atom has 6 protons, 6 neutrons, and 6 electrons. Determine the
atomic number, mass number, and the number of protons, neutrons,
and electrons in this carbon atom.
Step-by-step solution: 1. The atomic number of an element is
equal to the number of protons in its nucleus. Since the carbon atom
has 6 protons, its atomic number is 6. 2. The mass number of an
element is equal to the sum of the number of protons and neutrons
in its nucleus. In this case, the carbon atom has 6 protons and 6
neutrons, so its mass number is 6 + 6 = 12. 3. The number of
protons in an atom is always equal to its atomic number. Therefore,
the carbon atom has 6 protons. 4. The number of neutrons in an
atom is equal to the mass number minus the atomic number. So, the
carbon atom has 12 - 6 = 6 neutrons. 5. The number of electrons in
5
a neutral atom is equal to the number of protons. Since the carbon
atom has 6 protons, it also has 6 electrons.
Question 8
Step 1: Identify the atomic number and mass number - Atomic
number (Z) = 20 - Mass number (A) = 40
Step 2: Determine the number of protons (p+) - The number of
protons is equal to the atomic number p+ = Z p+ = 20
Step 3: Find the number of neutrons (n0) - Neutrons can be cal-
culated by subtracting the number of protons from the mass number
n0 = A - p+ n0 = 40 - 20 n0 = 20
Step 4: Calculate the number of electrons (e-) - For a neutral
atom, the number of electrons is equal to the number of protons e-
= p+ e- = 20
Answer: The atom has: - 20 protons - 20 neutrons - 20 electron-
sQuestion 8: Calculate the number of protons, neutrons, and elec-
trons in an atom with the following information: - Atomic number =
20 - Mass number = 40
Step 1: Identify the atomic number and mass number - Atomic
number (Z) = 20 - Mass number (A) = 40
Step 2: Determine the number of protons (p+) - The number of
protons is equal to the atomic number p+ = Z p+ = 20
Step 3: Find the number of neutrons (n0) - Neutrons can be cal-
culated by subtracting the number of protons from the mass number
n0 = A - p+ n0 = 40 - 20 n0 = 20
Step 4: Calculate the number of electrons (e-) - For a neutral
atom, the number of electrons is equal to the number of protons e-
= p+ e- = 20
Answer: The atom has: - 20 protons - 20 neutrons - 20 electrons
Question 9
Step 1: Determine the atomic number: The atomic number is
equal to the number of protons in an atom. In this case, the atom
has 6 protons. Therefore, the atomic number is 6.
Step 2: Determine the mass number: The mass number is equal
to the sum of the number of protons and neutrons in an atom. In this
case, the atom has 6 protons and 6 neutrons. Therefore, the mass
number is 6 + 6 = 12.
Step 3: Determine the symbol of the atom: The symbol of an
element is determined by using the atomic number and the mass
number. The symbol is written as follows:
Symbol =element’s symbol −atomic number −mass number
6
In this case, the element is carbon with an atomic number of 6 and
a mass number of 12. Therefore, the symbol of the atom is:
Symbol =C−6−12
Symbol =12
6C
Thus, the atomic number is 6, the mass number is 12, and the
symbol of the atom is 12
6C.Question 9: An atom has 6 protons, 6 neu-
trons, and 6 electrons. Determine the atomic number, mass number,
and the symbol of the atom.
Step 1: Determine the atomic number: The atomic number is
equal to the number of protons in an atom. In this case, the atom
has 6 protons. Therefore, the atomic number is 6.
Step 2: Determine the mass number: The mass number is equal
to the sum of the number of protons and neutrons in an atom. In this
case, the atom has 6 protons and 6 neutrons. Therefore, the mass
number is 6 + 6 = 12.
Step 3: Determine the symbol of the atom: The symbol of an
element is determined by using the atomic number and the mass
number. The symbol is written as follows:
Symbol =element’s symbol −atomic number −mass number
In this case, the element is carbon with an atomic number of 6 and
a mass number of 12. Therefore, the symbol of the atom is:
Symbol =C−6−12
Symbol =12
6C
Thus, the atomic number is 6, the mass number is 12, and the
symbol of the atom is 12
6C.
Question 10
Step-by-step solution: 1. An atom is the smallest unit of mat-
ter that retains the properties of an element, consisting of a nucleus
containing positively charged protons and uncharged neutrons, sur-
rounded by negatively charged electrons. 2. A molecule is a group of
two or more atoms bonded together, representing the smallest unit of
a compound that retains the chemical properties of that compound.
3. Atoms of different elements combine to form molecules through
chemical bonding, while atoms of the same element can also bond to
form molecules. 4. The properties of an atom depend on the number
of protons, neutrons, and electrons it contains, while the properties
of a molecule depend on the types and arrangement of atoms within
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it. 5. Atoms can exist independently or combine with other atoms to
form molecules, while molecules cannot exist independently and are
always composed of two or more atoms bonded together.Question 10:
Describe the differences between an atom and a molecule.
Step-by-step solution: 1. An atom is the smallest unit of mat-
ter that retains the properties of an element, consisting of a nucleus
containing positively charged protons and uncharged neutrons, sur-
rounded by negatively charged electrons. 2. A molecule is a group of
two or more atoms bonded together, representing the smallest unit of
a compound that retains the chemical properties of that compound.
3. Atoms of different elements combine to form molecules through
chemical bonding, while atoms of the same element can also bond to
form molecules. 4. The properties of an atom depend on the number
of protons, neutrons, and electrons it contains, while the properties
of a molecule depend on the types and arrangement of atoms within
it. 5. Atoms can exist independently or combine with other atoms to
form molecules, while molecules cannot exist independently and are
always composed of two or more atoms bonded together.
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it. 5. Atoms can exist independently or combine with other atoms to
form molecules, while molecules cannot exist independently and are
always composed of two or more atoms bonded together.Question 10:
Describe the differences between an atom and a molecule.
Step-by-step solution: 1. An atom is the smallest unit of mat-
ter that retains the properties of an element, consisting of a nucleus
containing positively charged protons and uncharged neutrons, sur-
rounded by negatively charged electrons. 2. A molecule is a group of
two or more atoms bonded together, representing the smallest unit of
a compound that retains the chemical properties of that compound.
3. Atoms of different elements combine to form molecules through
chemical bonding, while atoms of the same element can also bond to
form molecules. 4. The properties of an atom depend on the number
of protons, neutrons, and electrons it contains, while the properties
of a molecule depend on the types and arrangement of atoms within
it. 5. Atoms can exist independently or combine with other atoms to
form molecules, while molecules cannot exist independently and are
always composed of two or more atoms bonded together.
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