1. Matter and the Changes it undergoes
It MATTERS very much!
Matter and the Changes it undergoes

2. What is Chemistry?
Chemistry is the study of matter and the transformations it can undergo.
Matter is any substance that has mass and volume.
An atom is the smallest unit of matter that maintains its chemical identity.

3. Kinetic Molecular Theory
Describes the forces between molecules and the energy they possess.
Matter is made of atoms/molecules. Volume comes from the space between molecules.

4. Kinetic Molecular Theory
All molecules are in motion. The three states of matter have different motions.
When molecules collide with other molecules or the sides of containers, no energy is lost.

5. Solids
The intermolecular forces between molecules of solids are very strong.
Has a definite volume
Has a define shape
Low energy
Molecules in a solid move by vibrating in place.
Picture:

6. Liquids
The intermolecular forces between molecules of liquids are medium strength.
Has a definite volume
The shape depends on the container
Medium energy
Molecules in a liquid move by sliding past each other.
Picture:

7. Gases
The intermolecular forces between molecules of gas are very weak.
No definite shape
No definite volume
High energy
Molecules in a gas move by rapid, random motion.
Picture:

8. Phase Changes
A phase change is when molecules of a substance change spacing between molecules.
Causes:
change in temperature
change in pressure.

9. Melting
A solid becomes a liquid

10. Freezing
A liquid becomes a solid

11. Boiling
A liquid becomes a gas

12. Condensing
A gas becomes a liquid

13. Sublimination
A solid becomes a gas.

14. Deposition
A gas becomes a solid.

15. Phase Change Summary

16. Energy Changes Endothermic – heat is taken in by the object.
Exothermic – heat is released by the object.

17. Physical Properties
Describes characteristics of materials that can be observed without changing the material.
Color
Density
Hardness
Texture
Phase

18. Physical Changes
Physical changes affect the physical properties of a substance.
The chemical is the same before and after the change
Key Verbs:
Distill
Break
Boil
Melt
Heat

19. Chemical Properties/Chemical Change
Chemical properties describe how chemicals interact with each other
A new chemical is formed
Key verbs:
Bubbling, color change, new material
Burning
Combusting