which atom will have the highest ionization energy? p si c n

Answer:

D. N

Explanation:

Step1: Recall ionization - energy trend

Ionization energy increases across a period and decreases down a group.

Step2: Analyze the position of elements

C, N, Si, and P are considered. C and N are in the second - period, Si and P are in the third - period. Since ionization energy increases across a period, N has a higher ionization energy than C, and P has a higher ionization energy than Si. Also, since ionization energy decreases down a group, N (second - period) has a higher ionization energy than P (third - period). So N has the highest ionization energy among the given elements.