Final answer:
The electron configuration for the nitrogen anion (N³⁻) is [He]2s²2p⁶, the same as neon, indicating a filled valence shell for stability.
Step-by-step explanation:
The electron configuration for the nitrogen anion (N³⁻) involves adding three additional electrons to the neutral nitrogen atom configuration. A neutral nitrogen atom has an electron configuration of [He]2s²2p³. To form the N³⁻ anion, we add three electrons, filling the 2p orbitals.
Thus, the electron configuration for the N³⁻ anion is [He]2s²2p⁶, which is the same as the electronic configuration of neon (Ne), the next noble gas after helium in the periodic table. This complete electron configuration indicates a filled valence shell, making the anion more stable.