Which group on the Periodic Table of the Elements contains elements that react with oxygen to form compounds with the general formula X2O?
(1) Group 1 (3) Group 14
(2) Group 2 (4) Group 18
Group (1) is alkali metal and its elements have 1 valence electron. Oxygen (O) valency is 2, and together they can form compounds with the general formula X2O.