What is nickel’s electron configuration?

Nickel (Ni, atomic number 28) has 28 electrons. Its electron configuration is:

1s²  2s²  2p⁶  3s²  3p⁶  3d⁸  4s² or in condensed form: [Ar]  3d⁸  4s²

Explanation:

• The nearest noble gas to Ni is Argon (Ar, atomic number 18).
• After Argon, the next 10 electrons fill the orbitals in the order:
  • 4s orbital gets 2 electrons.
  • 3d orbital gets 8 electrons.
• Therefore, Ni has a ground-state configuration of [Ar] 3d⁸ 4s².

In excited states or in complexes, Nickel may also exhibit configurations like [Ar] 3d⁹ 4s¹ (due to stability reasons), but the standard ground-state configuration is [Ar] 3d⁸ 4s².

Final Answer: Nickel’s electron configuration is [Ar] 3d⁸ 4s².