Question

why carbon dioxide is not supports burning weather Oxygen and Carbon both supports burning

Answer 1

it is because carbondioxide is heavy gas then oxygen so it makes a blanket around burning substance and blocks the connection of oxygen towards burning substance and as we know for combustion we queried three things first oxygen then fule and a combustible substance

Answer 2

Carbon dioxide does not support burning because it excludes oxygen which is a key requirement for combustion (burning). Burning is an exothermic (energy releasing) reaction between a fuel and oxygen. Carbon dioxide is a gas denser than oxygen. When you apply it to a burning substance it displaces oxygen and the fire dies.