How many different principal quantum numbers can be found in the ground-state electron configuration of nickel?
A)2
B)3
C)4
D)5
E)6

Question

Quizplus · Accepted Answer

Nickel (Ni) has an atomic number of 28, meaning it has 28 electrons in its ground state. The electron configuration of nickel is [Ar] 3d^8 4s^2. This configuration involves electrons in the 3rd and 4th principal energy levels (n=3 for 3d and n=4 for 4s), as well as the electrons in the 1st and 2nd levels that are part of the [Ar] core (argon configuration, which ends at 3p^6). Therefore, nickel's electrons occupy the 1st, 2nd, 3rd, and 4th principal quantum levels in its ground state.

How Many Different Principal Quantum Numbers Can Be Found in the Ground-State