What is the formula for the compound that forms between barium and oxygen?

solution:

Barium is a chemical element with symbol Ba and atomic number 56. It is the fifth element in group 2 and is a soft, silvery alkaline earth metal. Because of its high chemical reactivity, barium is never found in nature as a free element

Oxygen is a chemical element with symbol O and atomic number 8. It is a member of the chalcogen group on the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as well as with other compounds.

Barium can form two distinct compounds with oxygen as the only other element in the compound: barium oxide with formula BaO and barium peroxide with formula BaO 2. The first of these compounds is more common and more stable.