Answer:
B) The group the atom is located
C) There needs to be 2 Na atoms and 1O atom to form Na2O
Liquid because it follows the shape of container
The order in which you would dig through the layers is
crust → upper mantle → lower mantle → outer core → inner core
See the image below.
I believe B) in both chemical changes and physical changes since in chemical changes, nothing is created or destroyed. In physical changes same thing but with matter.