Unit 4: #20-22

Question 1

20a. Look at the particle diagrams. Classify the substance represented in figure A.

Answer 1

Atoms of an element

Question 2

20b. Look at the particle diagrams. Does figure B represent a compound or an element? Explain.

Answer 2

Element: add the same, kind of atom

Question 3

20c. Look at the particle diagrams. Which diagram show only molecules? What is different about the various molecules shown in these pictures?

Answer 3

B: element.
C: compound.
D: mixture.

Question 4

21. Describe various ways in which a mixture could be physically separated, and the physical property being used to perform this separation.

Answer 4

Magnet – magnetism.
Filtration – particle size.
Centrifugation – density.
Chromatography – solubility.
Distillation – boiling point.

Question 5

22. Describe how the separation of hydrogen from oxygen and water is different from the examples provided in question 21.

Answer 5

It’s a chemical separation (bonds are broken) in a compound.