1. Matter & Its Properties
C 1.2

2. Matter
Can be defined as anything that has mass & takes up space
Mass is a measure of the amount of matter (using a balance)
Volume is the amount of 3D space an object occupies

3. Basic Building Blocks of Matter
Atoms are the smallest unit of an element that maintains the properties of that element
An element is a pure substance made only of 1 kind of atom
A compound is made from the atoms of 2 or more elements that are chemically bonded

4. Properties & changes in Matter
Properties are characteristics that chemists use to help distinguish & separate substances
Extensive properties depend on the amount of matter present (mass, volume, & amount of energy)
Intensive properties do not depend on the amount of matter present (BP, MP, density, ability to conduct)

5. Physical Properties
Physical properties are characteristics that can be observed or measured w/o changing the identity of the substance
They describe the substance itself such as MP and BP

6. A change that does not involve a change in the identity of a substance
Physical Changes
A change that does not involve a change in the identity of a substance
Grinding, cutting, melting, boiling
Changes of state (L to G, S to L)
Does not change the identity of a substance (ice is still H2O)
Video – changes in matter

7. Solid has a definite shape & volume
States of matter
Solid has a definite shape & volume
Particles are packed tightly together in relatively fixed positions
Liquid has definite volume but indefinite shape
Particles are close together but can move past each other

8. States of matter (cont.)
Gas has neither definite shape/volume
Particles move rapidly away from each other
Plasma is a high temperature state in which atoms lose their electrons

9. Change of state does not affect the identity of the substance
Changes of State
Change of state does not affect the identity of the substance
Melting
Freezing
Boiling

10. Chemical Properties
Relates to a substance’s ability to undergo changes that transform it into different substances
A new substance forms
The ability to burn or rust

11. Chemical Change/Reaction
A change in which 1 or more substances are converted into different substances
Substances that react in a chemical change are the reactants
Substances formed are the products
Burning charcoal + oxygen -> CO2

12. Energy & Changes in Matter
Energy is always involved when physical & chemical changes occur
Energy can be light or heat
Can be absorbed or released but energy is never created or destroyed (law of conservation)

13. Classification of matter
Classified into 2 groups:
Pure substances – can be an element or compound & composition is the same throughout
Mixtures contain more than 1 substance & can vary in composition & properties

14. Mixtures
A blend of 2 or more kinds of matter, each retaining its own identity & properties
Parts are physically mixed together & can usually be separated
Composition must be specified

15. Mixtures (cont.)
Homogeneous mixtures are uniform in composition (same proportion of components throughout) – also called solutions
Heterogeneous mixtures are not uniform throughout (can see the separate parts)
Video – classifying matter

16. Has a fixed composition and every sample has:
Pure substances
Has a fixed composition and every sample has:
the exact same chemical & physical properties
Exactly the same composition
Are either elements or compounds

17. Lab Chemicals & Purity
Lab chemicals are treated as pure, but all chemicals have some impurities
Table 1.1 lists grades of chemical purity

18. 1a. Physical properties can be observed without changing the substance
Section review
1a. Physical properties can be observed without changing the substance
Physical – mass, volume
Chemical – ability to burn

19. 2 a. tearing paper – physical 2 b. melting wax – physical
Section review
2 a. tearing paper – physical
2 b. melting wax – physical
2 c. burning a log – chemical
3. Decide if it has:
definite shape/volume – solid
definite volume/indefinite shape – liquid
indefinite shape/volume – gas

20. Section review 3. Decide if it has: definite shape/volume – solid
definite volume/indefinite shape – liquid
indefinite shape/volume – gas

21. Section review
4. mixtures are made of more than one substance that are not chemically combined (retains its own properties), whereas pure substances have a definite, fixed chemical composition & has the same properties throughout