Which element is most reactive sodium, magnesium, or aluminum and why?

If the atomic mass of an atom is 34 and the atom contains 13 protons, how many neutrons does the atom contain?

Identify a specific example for each type of technology

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?