How many electrons in a silicon atom have n = 3 as one of their quantum numbers? how many electrons in a potassium atom have l = 0 as one of their quantum numbers? how many electrons in a mercury atom have n = 4 as one of their quantum numbers?

1) ₁₄Si 1s²2s²2p⁶3s²3p².
Principal quantum number (n=3) have four electrons (3s²3p²).
2) ₁₉K 1s²2s²2p⁶3s²3p⁶4s¹.
Azimuthal quantum number (l=o) have seven electrons (1s²2s²3s²4s¹).
3) ₈₀Hg [Xe] 4f¹⁴5d¹⁰6s².
Principal quantum number (n=4) have thirty-two electrons (4s²4p⁶4d¹⁰4f¹⁴).
The principal quantum number is one of four quantum numbers which are assigned to each electron in an atom to describe that electron's state.
The azimuthal quantum number is a quantum number for an atomic orbital that determines its orbital angular momentum and describes the shape of the orbital.