## Physics: Principles with Applications (7th Edition)

a. Group VII. This is fluorine. The outer electrons are $2s^{2}2p^{5}$. b. Group II. This is magnesium. The outer electrons are $3s^{2}$. c. Group VIII, aka Group 0. This is argon. The outer electrons are $3s^{2}3p^{6}$. d. Group I. This is potassium. The outer electron is $4s^{1}$.