MATTER
MATTER
Chemistry is the study of matter and the changes that it undergoes.
Matter is anything that has mass and and volume.
Mass is a measurement that reflects the amount of matter.
Volume is a measurement that reflects the amount of space filled.
THE ATOM
All matter is composed of atoms.
Atoms are made up of protons, neutrons, and electrons.
STATES OF
MATTER
Matter that exists on Earth can be classified as one of the three physical forms, known
as the States of Matter:
1) Solid – Definite shape & Definite volume
Definite (for both shape and volume) means that the container makes no difference
whatsoever.
2) Liquid – Indefinite shape & Definite volume
Indefinite shape means that the sample takes on the shape of the container.
3) Gas – Indefinite shape & indefinite volume
Indefinite volume means the sample would expand to fill the entire container. Only
gases do this.
SHAPE & VOLUME
OF MATTER
MATTER CAN CHANGE STATES
Matter can change states when energy is added or removed.
For example:
As ICE, a solid, is heated, it is converted into a liquid, known as WATER.
As WATER, a liquid, is heated, it is converted into a gas, known as STEAM.
And the opposite when cooled.
CLASSIFICATION OF MATTER
Matter can be further classified into two categories:
Pure Substances and Mixtures
Pure Substances can be further classified into two categories:
Elements and Compounds
Mixtures can be further classified into two categories:
Homogeneous mixtures and Heterogeneous mixtures
CLASSIFICATION OF MATTER
PURE SUBSTANCES
Pure Substances can be classified into two categories:
Elements and Compounds
Pure Substances always have the same composition. This is known as the
Law of Constant Composition.
For example:
The compound water is always composed of
2 Hydrogen atoms and 1 Oxygen atom
ELEMENTS
Elements contain only one type of atom.
For example:
The element gold is only made of gold atoms.
DIATOMIC ELEMENTS
Some elements only exist in nature as diatomic elements.
This means that they have 2 atoms of one element bonded together.
These 7 elements are H, N, O, F, Cl, Br, & I
COMPOUNDS
Compounds contain two or more different types of atoms bound together in
a particular way.
For example:
The compound carbon dioxide is made of
one carbon atom and two oxygen atoms.
CLASSIFICATION OF MATTER
MIXTURES
A mixture is a combination of two or more pure substances in which each pure
substance retains (keeps) its individual chemical properties. It is a combination of
elements and compounds.
A mixture has variable composition.
For example:
In a mixture of ocean water collected at the beach,
there is salt, water, and sand.
Mixtures can be separated physically by filtration & distillation.
Mixtures can be further classified into two categories:
Homogeneous mixtures and Heterogeneous mixtures
HOMOGENEOUS MIXTURES
Homogeneous mixtures have the same consistency throughout.
Homogeneous mixtures can either be a solution or an alloy.
Solutions may contain solids, liquids, or gases.
Alloys are a mixture of metals.
SOLUTIONS
Solutions may contain solids, liquids, or gases.
For example: AIR
A mixture of gases: Helium (He), Nitrogen (N2), Oxygen (O2), Neon (Ne),
Water vapor (H2O), Carbon dioxide (CO2), & Argon (Ar)
For example: Coca-Cola
A mixture of gas & liquid: carbon dioxide (CO 2) and soda.
For example: Salt water
A mixture of liquid & solid: water (H2O) and salt (NaCl)
ALLOYS
Alloys are a mixture of two metals or a metal and a nonmetal.
For example: Brass
A mixture of two metals: zinc and copper
For Example: Steel
A mixture of a metal and a nonmetal: iron and carbon
PHYSICAL PROPERTIES
OF MATTER
A physical property of matter can be observed or measured without changing
the sample’s composition.
Observations usually consist of some type of numerical measurement
(quantitative) although sometimes there is a characteristic (qualitative description)
of the property.
Groups of similar elements & compounds can be characterized by the physical
properties that they have in common.
Examples: Color, odor, volume, state (solid, liquid, gas), luster (shiny), density,
solubility, melting point, boiling point, electrical conductivity, malleability, and
ductility (ability to form wires)
CHEMICAL PROPERTIES
OF MATTER
A chemical property of matter is the ability of a substance to combine with
or change into a new substances.
Examples: Flammability (burning), rusting, digestion, growth, fermentation,
combustion, neutralization
PHYSICAL CHANGES
A physical change alters a substance without changing its composition.
The most common physical changes are those that involve a state change:
Solid  Liquid (melting, fusion), Liquid Gas (boiling, evaporation)
Solid Gas (sublimation) - Example: Dry ice
Gas  Solid (deposition) - Example: Frost
Gas  Liquid (condensation), Liquid Solid (freezing)
Other examples of physical changes are:
Grinding something into powder, chopping wood, etc.
CHEMICAL CHANGES
A chemical change involves one or more substances changing into a new
substance.
A chemical change means that the reacting compound(s) are changed into new
compounds or products.
A chemical change obeys the Law of Conservation of Mass because matter is
neither created nor destroyed, just rearranged. The actual atoms involved remain,
but they are rearranged into the new compounds.
The rearrangement is called a chemical reaction.
A chemical change is a process in which chemical bonds are broken and new
ones are made.
Chemical changes are called REACTIONS.
CHEMICAL CHANGES
Examples:
Silver tarnishing, a plant growing a leaf,
electrolysis (the splitting of a water molecule), combustion, iron rusting