1. Elements, Compounds, Mixtures

2. S8P1- b Pure Substances and Mixtures
Essential Questions:
Are pure substances and mixtures BOTH examples of matter?
How are pure substances and mixtures alike? How are they different?
Classify as either a pure substance or a mixture: compound, element, homogenous, heterogeneous.

3. Matter Matter is separated into two main classes:
Mixtures- where particles are different
Homogenous- looks the same (salt water)
Heterogeneous- looks different (candy mix)
Pure substances- where all particles are alike
Example, elements and compounds

5. Elements

6. Elements Pure substance consists of only one kind of atom,
cannot be broken down into a simpler type of matter by either physical or chemical means, and
can exist as either atoms (e.g. argon)
or molecules (e.g., nitrogen).

7. Elements
A molecule consists of two or more atoms of the same element, or different elements, that are chemically bound together.
Note that the two nitrogen atoms which comprise a nitrogen molecule move as a unit.

8. Compounds
This is H2O- Water!

9. Compounds
consists of atoms of two or more different elements bound together,
can be broken down into a simpler type of matter (elements) by chemical means (but not by physical means)

10. Compounds
has properties that are different from its component elements
always contains the same ratio of its component atoms.
Microscopic view of the molecules of the compound water (gas phase). Oxygen atoms are red and hydrogen atoms are white.

11. Molecule or Compound?

12. Mixtures
Heterogeneous- particles look different

13. Mixtures Homogenous- particles look the same throughout
Example: salt water

14. Mixtures
consists of two or more different elements and/or compounds physically intermingled
can be separated into its components by physical means
often retains many of the properties of its components.

15. Mixtures
Microscopic view of a gaseous mixture containing two elements (argon and nitrogen) and a compound (water).

16. Identify: element, compound or mixture

17. Let’s look at some examples of elements, compounds and mixtures: