Answer
[Ne] 3s² 3p⁶
Step-by-step explanation:
Neutral sulfur has an atomic number of 16.
Neutral sulfur has 16 electrons and 16 protons.
However, S²⁻ implies neutral sulfur has gain two more electrons.
So, S²⁻ is negatively charged (anion) and has 18 electrons.
Electronic Configuration
Neutal sulfur (S) → 1s² 2s² 2p⁶ 3s² 3p⁴ → [Ne] 3s² 3p⁴.
Charged sulfur (S²⁻) → 1s² 2s² 2p⁶ 3s² 3p⁶ → [Ne] 3s² 3p⁶.
Therefore, the electron configuration of S²⁻ is [Ne] 3s² 3p⁶.