1. Mixtures ,Elements & Compounds
Describing Matter
Mixtures ,Elements & Compounds

2. Mixtures, Elements, Compounds
Scientists like to classify things.
One way that scientists classify matter is by its composition (What it is made up of).
Ultimately, all matter can be classified as mixtures, elements and compounds.
Salad
Gold
Salt (NaCl)

3. Why isn’t it a good idea to classify matter by its phases
Why isn’t it a good idea to classify matter by its phases? (solid, Liquid, Gas)
Because one kind of substance can exist in more than one phase – such as H20. And matter changes phases rather easily.

4. Why isn’t matter classified according to its physical characteristics, such as color?
Scientists wouldn’t find it very useful to group gold, sunflowers, and the sun together.

5. To identify a mixture scientists ask themselves…….
Is the matter uniform throughout?
Can it be separated by physical means?
Can it be separated by chemical means?
C12H22O11
Jellybeans

6. Mixtures: a blend of at least 2 substances. They can be either;
Heterogenoues-not uniform
Homogenoues-uniform
Chocolate chip cookies
Soil
Gravel
Kool aid
Salt
Air
water

7. Can it be separated by physical means?
If the answer is yes, the matter is a homogeneous mixture or solution.
If the answer is no its an element or a compound
Homogenoues Mixtures (solutions)

9. Solutions are homogenous mixtures Air is a solution of oxygen and other gases dissolved in nitrogen

10. Examples of heterogeneoues mixtures
Sand and pebbles
Oil and water
Granite
Considered the “least mixed.”
Does not appear to be the same throughout.
Particles are large enough to be seen.
Can be separated from the mixture.

11. AIR IS A SOLUTION
A homogeneous mixture in which there is both a solute and solvent present is also a solution.

12. Ocean water is a solution
Salt is dissolved (solute) into water (solvent)

13. Metals dissolved in metals are called alloys.
Types of solutions The substance that is dissolved is the solute and the substance that does the dissolving is the solvent.
Example
Solute
Solvent
Gas
Air (oxygen in nitrogen)
Liquid
Soda water (Co2 in H20)
Solid
Ocean water (salt in water)
Solid
Gold jewelry (copper in gold)
Metals dissolved in metals are called alloys.

14. Alloys Stainless steel is a mixture of iron and chromium.
Brass is an alloy of copper
and zinc.

15. The universal solvent: Water

16. Colloids
In a colloid the particles are mixed together but not dissolved.
The particles are relatively large and are kept suspended.

18. Separation of a Mixture
Components of dyes such as ink may be separated by paper chromatography.

19. Separation of a Mixture
Distillation: takes advantage of different boiling points.
NaCl boils at 1415 oC

20. Separation of a Mixture
Iron filings and sulfur (use magnet)
Evaporation and Filtration

21. Classification of Matter

22. ELEMENTS

23. Can it be separated by physical means
Can it be separated by physical means? If the answer is no, the matter is a pure substance.
An Element
A Compound
All elements are made of atoms.
Atoms of the same element are alike.
Atoms of different elements are different
Compounds are also pure substances.
--made from more than one element.
Water is a compound.
Water can be broken down into simpler substances – hydrogen and oxygen.

24. Common Elements Aluminum Al Bromine Br Calcium Ca Carbon C Gold Au
Helium He
Hydrogen H
Nitrogen N

25. Compound vs. Mixture Compound Mixture Made of one kind of material
Made of more than
one kind of material
Made by a
chemical change
physical change
Definite
composition
Variable

27. Which is it?
Compound
Mixture
Element

28. Element, Compound, or Mixture?
Rocks

29. Element, Compound, or Mixture?
Rocks

30. Element, Compound, or Mixture?
Copper

31. Element, Compound, or Mixture?
Copper Cu

32. Element, Compound, or Mixture?
Jelly Beans

33. Element, Compound, or Mixture?
Jelly Beans

34. Element, Compound, or Mixture?
Table Sugar

35. Element, Compound, or Mixture?
Table Sugar
C12H22O11

36. Element, Compound, or Mixture?
Diamond

37. Element, Compound, or Mixture?
Diamond C

38. Element, Compound, or Mixture?
Tea

39. Element, Compound, or Mixture?
Tea

40. Element, Compound, or Mixture?
Salt

41. Element, Compound, or Mixture?
NaCl
Salt

42. Element, Compound, or Mixture?
Neon Gas

43. Element, Compound, or Mixture?Ne
Neon Gas

44. Element, Compound, or Mixture?
Salad

45. Element, Compound, or Mixture?
Salad

46. Element, Compound, or Mixture?
Pure Water

47. Element, Compound, or Mixture?
Pure Water
H2O

48. Element, Compound, or Mixture?
Aluminum

49. Element, Compound, or Mixture?
Aluminum Al

50. Element, Compound, or Mixture?
Lemonade

51. Element, Compound, or Mixture?
Lemonade

52. Element, Compound, or Mixture?
Silver

53. Element, Compound, or Mixture?
Silver Ag

54. Element, Compound, or Mixture?
Sand

55. Element, Compound, or Mixture?
Sand