1. a) Igneous.
2. c) Metamorphic.
3. b) It broke into sediment and then compacted.
4. d) All types of rocks.
5. a) Wind and rain break down the rock into small pieces.
6. a) Yes, but it should be subtuced first.
7. c) Earth's interior.
8. c) Water.
9. b) Magma is molten rock within the Earth; lava is molten rock on the Earth's surface.
20.
Atomic number is equivalent to its protons and electrons. :)