1. Classifying Matter: Elements, Compounds, and Mixtures
8th Grade Science
2009

2. Matter is…. What is matter?
Anything that takes up space (volume) and has mass.
Water Rocks
Air Wood
Plastic You

3. How is matter classified?
Scientists like to classify things.
One way that scientists classify matter is by its composition.
Ultimately, all matter can be classified as elements, compounds and mixtures
Elements and compounds are pure substances
Mixtures are not pure substance

4. What are Pure Substances?
Elements
Atoms
Molecules
Compounds
A sample of matter that has a definite composition and definite chemical and physical properties

5. What are Elements? Made of one type of atom
Cannot be separated into simpler substance by physical or chemical means.
Located on the periodic table

6. What are atoms? The smallest part of an element
Atoms are the basic building blocks of all matter
Atoms chemically joined together are called molecules

7. How are elements represented?
Elements have names and chemical symbols of either 1 or 2 letter
H He Hydrogen Helium
Some are natural and some are synthetic (man made)
Currently there are about 118 known elements

8. H2O NaCl CO2 What are Compounds?
Are made of 2 or more atoms of different elements that are bonded together
Made of elements in a specific ratio
that is always the same
Has a chemical formula
Can only be separated by
chemical means, not physically
H2O
NaCl
CO2

9. What are Mixtures?
A combination of two or more pure substances that are not chemically combined.
substances held together by physical forces, not chemical
No chemical change takes place
Has a random composition
Each item retains its properties
in the mixture
They can be separated physically
Chem4kids.com

10. Is it uniform throughout?
Matter is also classified by its uniformity
If the answer is no, the matter is a heterogeneous mixture.
Considered the “least mixed.”
Does not appear to be the same throughout.
Particles are large enough to be seen and to be separated from the mixture.

11. Is it uniform throughout?
If the answer is yes, the matter is homogeneous (looks the same throughout).
If it can’t be physically separated it’s a homogeneous mixture
If it can not be separated then it is a pure substance –element or compound

13. Mixtures vs. Compounds

14. Can you identify the following?
You will be shown a series of photos. Tell if each photo represents an item composed of an element, compound, or mixture.
Review:
An element contains just one type of atom.
A compound contains two or more different atoms joined together.
A mixture contains two or more different substances that are only physically joined together, not chemically.
A mixture can contain both elements and compounds.

15. Element, Compound, or Mixture?
Rocks

16. Element, Compound, or Mixture?
Rocks

17. Element, Compound, or Mixture?
Copper

18. Element, Compound, or Mixture?
Copper Cu

19. Element, Compound, or Mixture?
Jelly Beans

20. Element, Compound, or Mixture?
Jelly Beans

21. Element, Compound, or Mixture?
Table Sugar

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

23. Element, Compound, or Mixture?
Diamond

24. Element, Compound, or Mixture?
Diamond C

25. Element, Compound, or Mixture?
Tea

26. Element, Compound, or Mixture?
Tea

27. Element, Compound, or Mixture?
Salt

28. Element, Compound, or Mixture?
NaCl
Salt

29. Element, Compound, or Mixture?
Neon Gas

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

31. Element, Compound, or Mixture?
Salad

32. Element, Compound, or Mixture?
Salad

33. Element, Compound, or Mixture?
Pure Water

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

35. Element, Compound, or Mixture?
Aluminum

36. Element, Compound, or Mixture?
Aluminum Al

37. Element, Compound, or Mixture?
Lemonade

38. Element, Compound, or Mixture?
Lemonade

39. Element, Compound, or Mixture?
Silver

40. Element, Compound, or Mixture?
Silver Ag

41. Element, Compound, or Mixture?
Sand

42. Element, Compound, or Mixture?
Sand

44. Notes Detailed notes are located at:
mixtures-notes-isn.pdf
Flow Chart:
isn.pdf