We know that the oxygen (O2) causes a glowing
splint to reignite, however, let us check what is missing on the products side
of the chemical equation:
KBrO3 → KBr + ?
As we see, oxygen (O2) is the element missing from the other
side. Therefore the balanced chemical
equation for this decomposition is as follows:
2KBrO3 → 2KBr + 3O2
