We wanted to know how temperature affected the volume of a gas. we investigated this by filling a balloon with air and heating and cooling it, comparing the circumference of the balloon before and after. our results showed the balloon got bigger when heated and smaller when cooled. these results support our hypothesis. a. the gas temperature will not impact the circumference of the balloonb. gases contract when heated and expand when cooledc. the gas temperature will not impact the circumference of the balloon. d. gases expand when heated and contract when cooled