1. Properties and Changes of Matter
Chapter 1 Section 1.2
Properties and Changes of Matter

2. Physical and Chemical Properties
Properties (characteristics) of matter can be described as either:
Physical
Chemical

3. What is a Physical Property?
These are properties that don’t involve changes in composition.
Qualitative examples:
The solution is blue
The tree is tall
The butter is soft
The liquid freezes at a low temperature
Quantitative examples:
Ice melts at 0°C
Iron has a density of 7.86g/mL

4. Physical Properties State of matter (change in state) Conductivity
Magnetic
Color
Melting point, boiling point
Density
Malleability

5. What is a Chemical Property?
These are properties that can be observed when there IS a change in the composition of the substance. (Change in composition)
Examples:
Oxidizer
Reactive
Flammable

6. Physical Change
Change of matter where its identity does not change (Doesn’t change what it is)
Cutting of paper
Sharpening of pencil
Ice melting into water

7. Chemical Change
Change of matter where its identity is changed (Changes what it is). Usually related to a chemical reaction.
Decomposition
Explode
Rot
Rust (oxidation)
Color change
Tarnish
Ferment

8. How do I know if it is a Chemical or Physical Change?
Ask the question – Do you end up with the same stuff you started with?
Yes, physical change
No, chemical change

9. Chemical Change and Atoms
Law of conservation of mass (matter)
- In a chemical change, matter is neither created nor destroyed.
Example:
CH4 + 2O2  CO2 + 2H2O
No atoms are gained or lost…

10. Chemical Change and Energy
Energy is the capacity to do work.
Energy is either absorbed or released in a chemical change.
Chemical reactions that give off heat energy are called exothermic reactions
Chemical reaction that absorb heat energy are called endothermic reactions

11. Endothermic Examples Absorbs heat and cools surroundings
Melting (ice cubes)
Cooking an egg
Evaporation of sweat
Photosynthesis
Baking soda when baking

12. Exothermic Examples Gives off heat and increase temp of surroundings
Burning wood
Digestion of food
Freezing
Cellular Respiration
Metabolism
Combustion of ammonium nitrate

13. Exothermic and Endothermic