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Chapter1.part2.pdf
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Matter exists in one of three common physical states:
• Solid, Liquid, and Gas
Chapter 1-part 2
Classification of Matter: States of Matter
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States of Matter
Solid: A substance that has a definite shape and
volume.
Solids are rigid, dense and incompressible.
Example:
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States of Matter
Liquid:
A substance that has a definite volume but that changes shape to fill the container (no definite shape).
• Liquids are dense, fluid, and incompressible.
Example
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States of Matter
Gas (vapor): A substance that has neither a definite
volume nor a definite shape. Gases are low density
fluids and are highly compressible.
Example:
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Classification of matter
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Elements: Pure substances
Elements are pure
substance that cannot be
broken down into other
simpler substances by
chemical or physical
means.
Elements are made of
one type of atoms.
Atoms are the smallest
part of an element
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Names of the Elements and symbols
About 100 elements have been discovered
Each element has a unique name.
Elements are represented by chemical symbols, consisting
of one or two letters, only the first of which is capitalized.
Example
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Elements and the periodic table
Elements are roughly divided into 3 groups: metals,
non metals and metalloids
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Properties of Metals
Property: A characteristic that can be used to describe
a substance.
– Shiny: Has metallic luster, Reflects light
– Opaque: Light does not pass through
– Malleable: Can be hammered into thin sheets without fracturing and are said to be malleable.
– Ductile Can be drawn into a fines wire and are said
to be ductile
– Conductive :Conducts both heat and electricity
– Solid at room temperature (except mercury, Hg which is a liquid)
– Metals form alloys
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Properties of metals
Alloys: mixtures of metals or mixtures of metals and non metals.
Example alloys:
• An amalgam is an alloy of two or more metals , one of
which is mercury
• Brass (an alloy of zinc and copper)
• Bronze (an alloy of metal tin and copper)
• Alloy of gold: Mixture of gold with other metals such as
copper, silver…….
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Properties of metals
-The purity of gold is expressed using the carat (K) system.
-Pure gold (100%) is termed 24 carat (K).
-18 K ring is 75% gold and 25% other metals in a gold
• Steel :alloy of iron and carbon (graphite, charcoal)
• Stainless Steel: iron, carbon and chromium
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Properties of metals
Alloys are used more extensively than pure metals because they can be engineered to have specific properties.
Steel : one of the most common material used in the world. It is also a major components in buildings, infrastructure, tools, ships, automobiles, appliances, machines, and weapons.
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Properties of Nonmetals are opposite of properties of metals
– Not shiny (Dull luster )
– not malleable not ductile (brittle in the solid state )
– non conductors of heat and electricity
Properties of Nonmetals
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Metalloids: Their properties are between those of metals and nonmetals.
(Boron (a) (b) silicon
Properties of Metalloids
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Elements
List of elements to memorize
Horizontal row: 1
Hydrogen (H)
Helium (He)
Horizontal row: 2
Lithium (Li)
Beryllium (Be)
Boron (B)
Carbon (C)
Nitrogen (N)
Oxygen (O)
Fluorine (F)
Neon (Ne)
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Elements
List of elements to memorize Horizontal row:3
Sodium (Na)
Magnesium (Mg)
Aluminum (Al)
Silicon (Si)
Phosphorus (P)
Sulfur (S)
Chlorine (Cl)
Argon (Ar)
Horizontal row: 4
Potassium (K); Calcium (Ca); Chromium (Cr); Manganese (Mn); Iron (Fe);
Cobalt (Co); Nickel (Ni); Copper (Cu); Zinc (Zn); Arsenic (As); Bromine (Br)
Krypton (Kr)
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Elements
List of elements to memorize
Horizontal row: 5
Palladium (Pd)
Silver (Ag)
Iodine (I)
Horizontal row: 6
Barium (Ba)
Platinum (Pt)
Gold (Au)
Mercury (Hg)
Lead (Pb)
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Compounds: Pure substances
Compounds are formed when two or more
elements combined chemically in specific ratios
to form a pure substance (John Dalton and the Atomic Theory of Matter)
A compound always contains the same elements
in certain definite proportions. (Law of definite proportions: 1799, Proust)
Example
Compounds can be chemically separated into individual
elements.
Example
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Mixtures
A mixture: physical blend (or a combination) of two or
more pure substances
Mixtures can be physically separated into its
component substances.
Example
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Mixtures.
A homogeneous mixture has a
uniform composition throughout and
is better known as a solution.
Heterogeneous mixtures are not
uniform in composition.
In many cases the heterogeneity of
a mixture can be seen by the naked
eye.
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Separation of Mixtures: Filtration
In filtration solid
substances are
separated from
liquids and
solutions.
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Separation of Mixtures:Distillation
Distillation uses differences in the boiling points of substances to separate the constituents of a liquid mixture into its components.
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Chemical Formula: A notation for a chemical compound using symbol of elements and subscripts to show how many
atoms of each element are present.
When no subscript is given for an element a subscript of “1” is
understood.
Example
Some chemical formulas use parentheses to clarify atomic composition.
Example:
Chemical Formulas
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Atoms and Molecules
Elements are made of one type of atoms.
Some elements exist as a single atom
Example:
Some elements exist as molecules (groups of atoms)
Example :
A unit of matter composed of two or more nonmetal elements is a molecule
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Molecules
Some compounds exist as molecules (nonmetals and nonmetals)
Example
Other compounds exist as ionic compounds (metals and nonmetals)
Example
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Molecules
Diatomic molecules: Molecules containing two atoms per molecules.
7 elements exist as diatomic molecules:
Hydrogen (H2); Nitrogen (N2); Oxygen (O2);Fluorine (F2);Chlorine (Cl2); Iodine (I2); Bromine (Br2)
Some compounds exist as diatomic molecules
Example
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Scientific notations
Scientific notation: used to write very large or very small numbers.
Example:
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• .
Writing numbers in Scientific Notation
A number written in scientific notation contains a
coefficient and a power of ten.
coefficient power of ten unit
• 1.5 × 102 m
The coefficient is at least 1 but less than 10
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Measurement of Matter
Physical properties such as mass, height, volume, and
temperature that can be measured are called physical
quantities.
Both a number and a unit of defined size is required to
describe physical quantity.
Unit = standard representation of physical quantities
A number without a unit is meaningless
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To avoid confusion, scientists have agreed on a standard set of
units.
Scientists use SI or the closely related metric units.
The metric system offers simplicity with a single base unit for
each measurement.
. Measurement of Matter
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Metric System: Memorize!
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Metric System: Memorize!
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Metric System and prefixes: Memorize!
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Converting a Quantity from One Unit to
Another
Factor-Label Method: an handy way to convert from
one unit to another.
A conversion factor : A ratio of two different units, used as a
multiplier to change from one system or unit to another.
Example: in class
(Starting quantity) x (Conversion factor) = Equivalent quantity
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Density
Density is an important physical property.
Density is defined as the amount of matter in a
given amount of space.
Memorize!
Density = mass / volume or d = m/V
Density helps convert mass to volume or mass to
volume
Example:
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Density
The density of water is 1 g/cm3 or 1 g/mL
Substances having higher densities than water will sink in
water, those having lower densities than water will float on
water.
Example: in class
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Energy
Energy: The capacity to do work or supply heat.
Energy can be described as:
• Potential energy is stored energy (The energy an
object has, the energy stored in an object.
• Kinetic energy is energy in motion (A moving
object possess a kinetic energy.
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Energy:
Energy exists in many different forms.
Examples :Heat , Light, Chemical ,Electrical, Mechanical ,
Nuclear
Mechanical energy, light, heat, and electrical energy are
example of kinetic energy.
Chemical energy and nuclear energy are example of potential
energy.
Example: Chemical energy is stored in chemical substances as,
for example, in foods such as carbohydrates and fats.
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Heat vs. Temperature
Heat: energy that is transferred from hotter
objects to cooler objects.
Temperature: the measure of how hot or
cold an object is. (It also measures the
energy of a particles in a given sample)
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Units of Heat
• Heat energy is often measured in calories or joules.
• 1 kilocalorie = 1 kcal = 1 Cal (Foods) = 1000 cal
• A kcal is called by nutritionists a large calorie (Cal)
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Temperature Scales
Temperature is commonly reported either in degrees
Fahrenheit (oF) or degrees Celsius (oC).
The SI unit of temperature is the Kelvin (K),the metric
system unit of temperature is degrees Celsius (oC).
Memorize!
K = oC + 273.15
oC = K - 273.15
