Question

which is the correct orbital energy diagram for nitrogen?

Explanation:

Step1: Determine the electron configuration of nitrogen

Nitrogen has an atomic number of 7, so it has 7 electrons. The electron configuration is \(1s^{2}2s^{2}2p^{3}\).

Step2: Apply Hund's rule

Hund's rule states that electrons will occupy degenerate (equal - energy) orbitals singly before pairing up. For the \(2p\) sub - shell (which has 3 degenerate orbitals), the 3 electrons in the \(2p\) sub - shell will each occupy one of the \(2p\) orbitals with parallel spins.

The \(1s\) and \(2s\) orbitals are completely filled (\(1s^{2}\) and \(2s^{2}\)), so they have paired electrons (opposite spins).

Answer:

The orbital energy diagram with \(1s\) (two electrons with opposite spins), \(2s\) (two electrons with opposite spins), and \(2p\) (three electrons, one in each of the three \(2p\) orbitals with parallel spins) is the correct one. So the third option (where \(1s\) and \(2s\) have paired electrons and \(2p\) has three unpaired electrons) is correct.