Final answer:
The Nitrogen family, or Group 15 (Group V), has a half-full p orbital, making option D the correct answer.
Step-by-step explanation:
The group with a half-full p orbital is the Nitrogen family or Group 15 (Group V). Elements in the Nitrogen family have five electrons in their p orbitals, which means the p orbital is half-full since it can hold a maximum of six electrons. Therefore, the correct answer is D. Nitrogen Family.
To clarify the other options:
- Alkali metals belong to Group 1 and have a single s orbital electron.
- Noble gases, in Group 18, have full outer energy levels.
- Halogens are in Group 17 and have seven valence electrons, with p orbitals one electron short of being full.