Lithium and oxygen react to form lithium oxide. What is the balanced equation for this reaction?

Lithium is Li

Oxygen gas is O2

Lithium oxide is Li2O

Unbalanced Equation is Li + O2 - - > Li2O

There's one O on right side, 2 Os on left, so make coefficient 2 on right side to balance the oxygens.

Li + O2 - - > 2 Li2O

Now balance the lithiums. There are 4 Lis on right side; 1 Li on left, so make Li coefficient 4 to balance the lithiums.

4 Li + O2 - - > 2 Li2O

This equation is now fully balanced.

Therefore balanced equation is:

4 Li + O2 - - > 2 Li2O