2. Pure Substances
Every sample of a given substance has the same
properties because a substance has a
fixed, uniform composition.

3. Elements and Compounds
An element has a fixed composition because it
contains only one type of atom.
One capital letter
A compound always contains two to more
elements joined in a fixed proportion.
More than one capital letter

4. The properties of a
mixture can vary
Mixtures because the
composition of a
mixture is not fixed.
Heterogeneous Homogeneous
Comes from the Greek One mixture so thoroughly
words: dissolved in another
mixture that it is hard to
distinguish between the two
Hetero: Different: in the mixture.
Geneous: Kind Ex: salt water.

5. Colloids
Suspensions,
Solutions,
Based on the size of its largest
particles, a mixture can be classified as a
solution, a suspension, or a colloid.
Solution
A homogeneous mixture that does not
separate into layers over time
Can be seen through
Must be separated chemically

6. Colloids
Suspensions,
Solutions,
Based on the size of its largest
particles, a mixture can be classified as a
solution, a suspension, or a colloid.
Suspension
A heterogeneous mixture that separates into
layers
Can be separated physically

7. Colloids
Suspensions,
Solutions,
Based on the size of its largest particles,
a mixture can be classified as a solution,
a suspension, or a colloid.
Colloid
Particles in between solutions and
suspensions.
Do not separate into layers
Cannot be separated by a filter

8. Lava with high Lava with low
viscosity viscosity
Viscosity
• The thickness of a liquid
• The higher viscosity, the thicker the liquid.

9. Separation techniques
Distillation
A process that separates a solution based on boiling
points

10. Separation techniques
Filtration
A process that separates materials based on the size of
their particles and/or solubility.

11. Separation techniques
Evaporation
A process used to isolate a solid dissolved in a liquid,
Property: solubility

12. Flammability
Flammability is a material’s ability to burn in the
presence of oxygen.
The ability to burn is not a physical property
because you cannot observe burning without
changing the composition of the of the material
that is burning.

13. Reactivity
Reactivity is the property that
describes how readily a substance
combines chemically with other
substances.

14. Chemical and Physical
Changes

15. Precipitates
Any solid that forms and separates from a liquid
mixture is called a precipitate.

16. Review Question One

17. Review Question Two

18. Review Question Three

19. Review Question Four

20. Review Question Five