Question

What happens when Ba (barium) and O (oxygen) combine?

Answer 1

Barium reacts with oxygen when exposed to air, forming a thin passivating layer of BaO on the surface. When ingnited, barium reacts with both oxygen and nitrogen, forming a mixture of BaO, Ba 3N 2 and BaO 2.

Step-by-step explanation:

Answer 2

So, one ion of barium neutralizes one ion of oxygen, and so those two combine to form barium oxide, BaO .