pressure. but if you are in middle school then look in your textbook for all of your answers it will help you so much more than the internet.
The mass number is c number of protons and neutrons in a atom
Answer:
Compositional Layers
The Earth has different compositional and mechanical layers. Compositional layers are determined by their components, while mechanical layers are determined by their physical properties. The outermost solid layer of a rocky planet or natural satellite.