The difference between a solid and a gas is that
A. solids can change their volume but gases
cannot.
B. solids can take the shape of its container, and
gases cannot.
C. solids have high energy levels and gases have
low energy levels.
D. solids have low energy levels and gases have
high energy levels.

What are the first two quantum numbers for the electrons located in subshell 4d? what are the first three quantum numbers for the electrons located in subshell 2s? how many electrons can be held in a sublevel l = 3? how many electrons can be held in the energy level n = 4? how many electrons in an atom can share the quantum numbers n = 4 and l = 3?