The answers are:
1. Compaction - grains move closer together.
2. Foliation - parallel alignment of platy grains.
3. Recrystallization - grains take on a larger size.
4. Burial metamorphism - when a rock changes because of surrounding pressure.
Compaction produce rocks that have a tighter grain arrangement due to heat and pressure the rock undergoes. This process reduces the size of the rock.
Foliation occurs when pressure is put on one side of the grains more than any other direction. This creates platy structured rocks, which align under pressure.
Recrystallization is a process where the chemical composition a rock is changed. The mineral grains that are produced in this process are larger than the original grains.
Burial metamorphism occurs when rocks get buried deeper and deeper. They change due to the pressure from the overlying layers.
