1. Classifying Matter

4. Substances (Pure substances)
Materials that has uniform, fixed composition and properties and cannot be broken down by physical separations.
Exist in their simplest form, maintaining properties.

6. Mixtures Combinations of pure substances.
Can be separated by physical means.

8. Physical Separations
separation of a mixture that does not change the composition of the components.
Chromatography – “separation by color” separate chemicals by their wavelength and polarity – uses chemical affinities.
All of the materials that make that mixture up are available after separation.
Ex. Separation by: Gravity, Filtration, Boiling, etc.

12. Compounds
Substances that are combinations of different types elements in a fixed ratio.
Atoms are fixed via Chemical Bond
Compounds can also be known as
formula units or molecules
(depending on how they chemically combine)

14. Chemical Separations
Separation of substances due to a chemical property that is taken advantage of or a separation that alters chemical composition.
Electrolysis – Use electricity to decompose a substance. Alters composition.

18. Homogeneous Mixtures
Mixture of substances that appears to have a consistent composition throughout.
There are no clear separations of materials – single phase mixture
Homogeneous mixtures of metals are called alloys.

19. Heterogeneous Mixtures
Mixture of substances that does not appear to be consistent throughout – clear separations.
Also called multi-phase mixtures. (2 phase, 3 phase, etc.)
Different shapes, different densities, different materials.

20. SOLUTION
COLLOID
SUSPENSION
Particle size

21. Mixtures (cont.) Solutions vs. Colloids
smallest particles
Homogeneous
Transparent, completely allows light to pass through.
Homogeneous
Exhibit Tyndall Effect
Light passes through in the form of a beam due to light colliding with larger sized particles.

22. Mixtures (cont.) Colloids vs. Suspensions
Homogeneous
Particles will NOT “settle out”.
EX: Jello, Fog, Milk
Heterogeneous
Particles can be filtered or settle out.
EX: Muddy water