Answer:
4K + O2 ---> 2K2O
Explanation:
The valence of Potassium is +1
The valence of oxygen is -2
Thus, two atoms of potassium will attach with one atom of oxygen to form molecule of potassium oxide.
This can be written as
2K + O ---> K2O
However, this is not the balanced equation as oxygen exists as O2 molecule.
Thus, the balanced equation is
4K + O2 ---> 2K2O
