1. Chapter 2 – Matter & Change
Matter is anything that has mass and takes up space
Mass is the amount of matter an object contains
Volume is the amount of space an object occupies

2. Chapter 2 – Matter & Change
Matter can exist in four states
Solid
Liquid
Gas
Plasma

3. Chapter 2 – Matter & Change
Matter can be classified into two main groups
Pure Substance
Mixture
A pure substance is a material with a definite composition and fixed properties
Pure substances are divided into two groups
Elements
Compounds

4. Chapter 2 – Matter & Change
An element is a pure substance with only one kind of atom
All elements are found in the periodic table
There are about 118 known elements
Elements are represented with a chemical symbol
Many symbols are based on the latin name
Each symbol begins with an uppercase letter and subsequent letters are always lowercase

5. Chapter 2 – Matter & Change
Compounds are two or more different elements chemically combined
Compounds are represented with a chemical formula
The formula tells what elements and how many atoms
CO2 is one carbon atom and two oxygen atoms

6. Chapter 2 – Matter & Change
Mixtures are a combination of two or more substances, where each substance maintains its identity
The major difference between a mixture and a compound is that mixtures are easily separated
There are two types of mixtures
Homogeneous
Heterogeneous

7. Chapter 2 – Matter & Change
A homogeneous mixture is a mixture that looks the same (uniform)
It has only one phase
Homogeneous mixtures are also called solutions
Solutions are composed of two parts
Solute – is being dissolved
Solvent – does the dissolving

8. Chapter 2 – Matter & Change
Not all solutions are liquid
Solid solution – gold jewelry
Liquid solution – gasoline
Gas solution – air

9. Chapter 2 – Matter & Change
A heterogeneous mixture looks different (non uniform)
Heterogeneous mixture may settle – orange juice

10. Chapter 2 – Matter & Change
Determine whether the following is an element, compound, homogeneous mixture, or heterogeneous mixture
Copper Rubbing Alcohol
Granite Salt
Carbon Dioxide Silicon
Soda Sugar
Concrete Helium
Salad Dressing Air
Stainless Steel Egg

11. Chapter 2 – Matter & Change
Another way scientists classify matter is according to properties
Properties are used to describe matter
Properties can be either
Intensive
Extensive

12. Chapter 2 – Matter & Change
An intensive property is independent on the amount of the sample
For example, the density of aluminum is always 2.7 g/cm3
Regardless if the sample is large or small
An extensive property is dependent on the amount of sample
A large sample of aluminum will have a greater mass than a smaller sample

13. Chapter 2 – Matter & Change
Properties can also be classified as
Physical
Chemical
A physical property is a property that can be observed without changing the composition of the substance

14. Chapter 2 – Matter & Change
A chemical property is a property that can only be observed when the composition of a substance changes

15. Chapter 2 – Matter & Change
Identify the following as either physical or chemical properties
Blue Color Density
Flammability Melting Point
Solubility Reacts with Acid to form H2
Supports Combustion Boiling Point
Sour Taste Reacts with a Base to Form Water
Hardness Luster
Can Neutralize a Base Odor

16. Chapter 2 – Matter & Change
Matter can also undergo changes
Matter may change its appearance but not its composition
That is a physical change
Physical changes can be reversible or irreversible

17. Chapter 2 – Matter & Change
Matter may change its appearance and its composition
That is a chemical change
Another name for a chemical change is a chemical reaction
The starting materials in a chemical reaction are called reactants
The ending materials in a chemical reaction are called products

18. Chapter 2 – Matter & Change
Chemical changes are usually accompanied with four possible clues
a transfer of energy
a change in color
the production of a gas
the formation of a precipitate

19. Chapter 2 – Matter & Change
Determine whether the following is a physical or chemical change.
Sodium hydroxide dissolves in water.
A pellet of sodium is sliced in two.
Water is heated and changed to steam.
Iron rusts.
Evaporation.
When placed in water, a sodium pellet catches on fire.
Sugar dissolves in water.
A tire is inflated with air.
Pancakes cooking on a griddle.
Food is digested in the stomach.

20. Chapter 2 – Matter & Change
Regardless if the change is physical or chemical, the Law of Conservation of Mass is observed
The Law of Conservation of Mass states that matter cannot be created or destroyed
Therefore the initial amount of substance must equal the final amount of substance.