1. Matter & Change
Chapter 2

2. 2.1: Properties of Matter
A substance is matter that has a uniform and unchanging composition. (pure substance)
A physical property is a characteristic that can be observed or measured without changing the composition of the sample.

3. 2.1 Cont. 2 types of Physical Properties
Extensive Properties depend on the amount of a substance.
Intensive Properties are independent of the amount of a substance.
A chemical property is the ability or inability of a substance to combine with or change into one or more other substances

4. 2.1 Cont. States of Matter Solid Liquid Gas Plasma
Definite shape & volume
Incompressible
Relatively slow moving particles
Tightly packed particles

5. 2.1 Cont. Liquid Gas (Vapor) Constant volume
Takes the shape of the container, flows
Less closely packed particles
Particles move more quickly
Virtually incompressible
Gas (Vapor)
Takes the shape of the container
Fills the container
Particles move rapidly
Particles far apart
Easily compressible

7. 2.1 Cont.
Types of Changes
Physical
Chemical
A physical change is a change that alters a substance w/o changing its composition.
Reversible & Irreversible
A chemical change is a process that involves 1 or more substances changing into new substances. (Chemical Reaction)

8. 2.2: Mixtures
Mixture
A combination of 2 or more pure substances in which each pure substance retains its individual chemical properties.
Types of Mixtures
Heterogeneous
Doesn’t blend smoothly throughout; individual substances remain visually distinct
Homogeneous
Constant composition throughout; always a single phase
solution

9. 2.2 Cont. Separating Mixtures Filtration Distillation Crystallization
Chromatography

10. Filtration

11. Distillation

12. Chromatography

13. 2.3: Elements & Compounds
Substances can be classified as elements & compounds.
An element is a pure substance that can’t be broken down into simpler substances by chemical or physical means.
91 elements naturally occurring on earth
About 120 known elements

14. 2.3 Cont.
A compound is two or more different elements combined chemically.
Approximately 10 million known compounds
Approximately 100,000 new compounds discovered every year.
Compounds can be broken into simpler substances by chemical means.
The properties of a compound are different than those of the individual elements

15. 2.4: Chemical Reactions Reactants Products
Clues a Reaction has Taken Place
Law of Conservation of Mass
Mass is neither created nor destroyed during a chemical rxn – it is conserved.
Mass reactants = Mass products