What subshells will be available for electrons to occupy

Question

Considering all electrons are in the ground state, for an energy level n=3, what subshells will be available for electrons to occupy for a neutral chromium atom

Answer 1

Chromium (Cr) is a transition metal located in period 4 group 6 and as such is a d-block element. The electron configuration is [Ar] 3d⁵4s¹. So if you are only considering n = 3, the subshells available would be the 3d subshells.