let's have a helium balloohere and 'sn contact with their in the room. won't it come to the same temperature? yes, it will. e air in this room all has the same tperature. that doesn't mean every molecule is going exactly as fast as the other. it means on the average they are. the average kinetic energy per molecule is the same for everything that has the samtemperature. so helium atoms move faster on the avera than others because they are... smaller. let's use the equation to guide our thinking. remember we talked about kinetic energy before, gang. let's get in a little physics here. now, this is kinda-- this is a little deep physics. that's the expression, kinetic energy. that is also proportional to temperature. to say two volumes of gas have the same temperature is to say those two volumes of gas have the same kinetic energy for their molecules. so the kinetic energy is the same. now, a helium atom has a very, very tiny mass and compared to the other maes ke the oxygen and nitrogen, they have large masses. so i could put the oxygen and nitrogen like t