Answer:
2Ba + O2 --> BaO
Explanation:
A combustion reaction is a reaction between a fuel with oxygen. Is this case, the fuel is Barium, which is a metal of group 2A, so it has 2 electrons in its valence shell. It must donate these 2 electrons to be stable and will be the cation \(Ba^{+2}\).
Oxygen is in group 6A, so it has 6 electrons in its valence shell, so must gain 2 electrons to be stable, and will be the anion \(O^{-2}\). So, they will form an ionic compound, and we need to change their charges without the signal to form its formula:
Ba2O2 = BaO
The reaction is:
Ba + O2 --> BaO
Balancing:
2Ba + O2 --> 2BaO
