Question

question 21 (1 point) which of the following elements has the highest ionization energy? nitrogen oxygen phosphorus sulfur carbon

Explanation:

Ionization energy increases across a period and decreases down a group in the periodic table. Nitrogen, oxygen, phosphorus, sulfur, and carbon are compared. Nitrogen and oxygen are in the second - period, while phosphorus and sulfur are in the third - period and carbon is also in the second - period. Nitrogen has a half - filled 2p sub - shell which gives it extra stability, making it harder to remove an electron compared to oxygen. Also, elements in the second period generally have higher ionization energies than those in the third period among these choices.

Answer:

Nitrogen