N electron affinity around what value?

N electron affinity around what value?

• A. 0; It has a half-filled 2p subshell.
• B. 50 kJ/mol
• C. -20 kJ/mol
• D. 100 kJ/mol

Answer: (A)

Electron affinity is the energy change when a neutral atom in the gas phase gains an electron. For nitrogen, the 2p subshell is half-filled (2p3), which is relatively stable because each p orbital contains one electron with parallel spins. Adding another electron would force pairing in one orbital, increasing repulsion and disrupting that stability. Because of this, nitrogen does not strongly favor gaining an electron, so the energy change is very small—essentially around zero. The other values imply a much larger tendency to gain an electron, which isn’t consistent with nitrogen’s half-filled 2p stability.

Electron affinity is the energy change when a neutral atom in the gas phase gains an electron. For nitrogen, the 2p subshell is half-filled (2p3), which is relatively stable because each p orbital contains one electron with parallel spins. Adding another electron would force pairing in one orbital, increasing repulsion and disrupting that stability. Because of this, nitrogen does not strongly favor gaining an electron, so the energy change is very small—essentially around zero. The other values imply a much larger tendency to gain an electron, which isn’t consistent with nitrogen’s half-filled 2p stability.