1. How many sides (or faces) does a silica octahedral have?

a. 2.

b. 6.

c. 4.

d. 8.

2. How many sides (or faces) does a silica tetrahedral have?

a. 2.

b. 6.

c. 4.

d. 8.

3. Postperovskite did not exist in the early earth because

a. the mantle was not convecting at a sufficient rate.

b. the Earth was still too hot.

c. the crust had not yet formed.

d. the core was mostly solid.

4. Although the composition of the mantle is roughly homogenous,what five minerals (listed in order by increasing depth) are foundin the mantle?

Olivine.   

Modified spinel.   

Spinel.

Perovskite.

Postperovskite.

CHOOSE: 1 (most shallow).   2.3.   4.   5 (deepest).        

5. True or false: the amount of postperovskite is likely todecrease in the future.

a. True

b. False