chemistry homework

Chemistry Homework:

1. Express each of these numbers in scientific notation.

a. 1500 m, the distance of a foot race

b. 0.0000000000958 m, the distance between O and H atoms in a water molecule

c. 0.0000075 m, the diameter of a red blood cell

d. 150,000 mg of CO, the approximate amount breathed daily

2. Write each of these values as a “regular” number.

a. 5.0 X 10⁻₃%, the concentration of CO in the air on a city street (the -3 is superscript)

b. 1 X 10 ⁻⁵ g, the recommended daily allowance of vitamin D

3. Common metals include iron, magnesium, aluminum, sodium, potassium, and silver. Give the chemical symbol for each.

4. Give the name and chemical symbol for five nonmetals not mentioned in #3.

5. Classy each of these substances as an element, a compound, or a mixture.

a. A sample of “laughing gas” (dinitrogen monoxide, also called nitrous oxide)

b. Steam coming from a pan of boiling water

c. A bar of deodorant soap

d. A sample of copper

e. A cup of mayonnaise

f. The helium filling a balloon

6. Using the periodic table as a guide, specify the number of protons and electrons in a neutral atom of each of these elements.

a. Magnesium (Mg)

b. Sulfur (S)

7. Give the name any symbol for the element with this number of protons.

a. 2

b. 19

c. 29