Write three differences between graphite and diamond.

Anthracite is

1. an inferior type of coal
2. a superior type of coal
3. a cheapest form of coal
4. none of the above

Lamp black is

1. an amorphous form of carbon
2. a crystalline form of carbon
3. a pure form of carbon
4. a cluster of carbon atoms

The process by which decayed plants slowly convert into coal is called

1. petrification
2. carbonization
3. carbonification
4. fermentation