1. Matter- Properties and Change
Chapter 3
Matter- Properties and Change

2. Properties of Matter
Matter can be defined as anything occupying space that has mass
A substance is matter that has a uniform and unchanging composition :
Example: Table salt or Water are pure substances

3. States of Matter
Solid: definite shape and volume, tightly packed, incompressible
Liquid: flows, constant volume, takes shape
of container
Gas: molecules are far apart and freely moving

5. Physical vs. Chemical Changes
Physical: difference appearance, same composition
Boiling water, breaking a crystal
Chemical: one or more substances
that change to form a different substance
Example: rust, fire
*color change, heat, formation of a gas are all indicators that a chemical change has occurred

6. Conservation of Mass (matter)
Mass of the reactants = Mass of Products
“Matter cannot be created nor destroyed but changes from one form to another”
Example: A 10.0 g sample of magnesium reacts with oxygen to form 16.6 g of magnesium oxide. How many grams of oxygen reacted?

7. Mixtures Heterogeneous mixture: substances remain individual
Example: sand and water
Homogeneous mixture:
constant composition throughout
= SOLUTIONS
Example: ice tea
* mixtures can be separated by physical means such as filtration, distillation, crystallization, and chromatography

8. Elements and Compounds
Elements: cannot be broken down into simpiler substances by chemical or physical means
Organized and predicted by periodic table- Mendeleev
Compound: chemically combined two or more elements

9. Law of definite proportions
The compound is always made up of the elements in the same proportion of mass
Percent by mass(%) = mass of element X100
mass of compound
Example: 500g of Sucrose was found to have g of Carbon. What percent by mass is Sucrose composed of Carbon?

10. Law of Multiple Proportions
Elements can form compounds in different ratios which are expressed in the chemical formula and can be calculated by percent mass.
Example: H2O and H2O2