The right answer is Li2O.
Lithium is the only alkali metal that can be handled in the air safely, while the others oxidize with, most often, inflammation. In dry air, lithium slowly overlies with a film of oxide and nitride. In moist air, the attack, catalyzed by water vapor, is much faster. The metal ignites in dry oxygen only above 200 ° C giving the oxide Li2O.
