Answer
a. \( \mathrm{N} < \mathrm{O} < \mathrm{F} \)
b. \( \mathrm{Al} < \mathrm{Si} < \mathrm{P} \)
Work Step by Step
a. The electron affinity generally increases from left to right within a period and decreases from top to bottom within a group on the periodic table. Therefore, the order from least negative electron affinity to most is \( \mathrm{N} < \mathrm{O} < \mathrm{F} \).
b. The electron affinity generally increases from left to right within a period and decreases from top to bottom within a group on the periodic table. Therefore, the order from least negative electron affinity to most is \( \mathrm{Al} < \mathrm{Si} < \mathrm{P} \).
