Question

How did oxygen get the 2? Which is O2.

Answer 1

Answer:

the number of molecules is 2

Answer 2

Answer:

Actually, O, oxygen isn't stable. So, its two atoms are combined together to get stable. As if you find the oxygen in air, it is O2, not O. They can be converted into O as you give heat energy in a very huge amount. But as the temperature again falls, then they'll again come to O2.