1. Properties and Composition
Matter
Properties and Composition

2. So What is Matter? Anything that occupies space and has mass
What isn’t mass?
Energy
Ideas
Sound
And…

3. Properties
Physical Property - any property that can be observed without transforming the substance into another substance
mass, color, freezing point
Chemical Property - any property that cannot be studied without transforming the substance into a different substance
iron rusts, paper burns

4. Properties
Intrinsic – does not depend on the amount of material you have
color, solubility, viscosity, malleability, boiling point, density
Extrinsic – depends on the amount of matter
mass, volume, length

5. Density Property derived from two measurements, mass and volume
Density = Mass/Volume
Will have a unit that contains both mass and volume such as g/cm3, lb/gal, kg/L
Does not depend on the size of the sample

6. Density
What is the density of a sample of metal that has a mass of g and when placed in 15.0 mL of water causes the level to rise to 22.4 mL?

7. CHM PGCC Barbara A. Gage

8. Changes
Physical Change - change that does not transform the substance into another substance
melting, subliming, dissolving

9. Changes
What were the physical changes that you encountered in activities on Day 2?

10. Changes
Chemical Change - change that transforms the substance into another substance
burning, oxidation of metal

11. Chemical Change CHM 1010 PGCC Barbara A. Gage
From Silberberg, Principles of Chemistry, 2007
CHM PGCC Barbara A. Gage

12. Distinguishing Between Physical and Chemical Change
PROBLEM:
Decide whether each of the following process is primarily a physical or a chemical change, and explain briefly:
(a) Frost forms as the temperature drops on a humid winter night.
(b) A cornstalk grows from a seed that is watered and fertilized.
(c) Dynamite explodes to form a mixture of gases.
(d) Perspiration evaporates when you relax after jogging.
(e) A silver fork tarnishes slowly in air.
SOLUTION:
(a) physical change
(b) chemical change
(c) chemical change
(d) physical change
(e) chemical change