Question

Why is it that we breath out carbon dioxide?

Answer 1

The carbon dioxide which we breath out is the one molecule of the sugar in the cell , that is you give of 6 molecules of co2 and 6 of water . Thats what u breath out..

Answer 2

we exhale carbon dioxide because our body need oxygen for cellular respiration. so the excess amount of oxygen will be sent out in exhalation process. so carbon dioxide is  exhaled out.