How are elements identified in terms of their atoms?

Iknow the answer to 13 is b and 14 is d. i just need to know why the correct answers are correct

Which of the following happens during cell division? (a) energy is created (b) waste is eliminated (c) carbon dioxide is released (d) damaged cells are replaced

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?