[BostonCard]

thanks for the explanations. I think the second part of the explanation for me is that the water molecules are not simply added to the air molecules in a given volume of dry air; at the same temperature they are in place of them so the overall density is lighter.
Whatever the explanation, I'm all for it as long as we hit many more home runs than them, with a higher density of baserunners when we hit 'em.

Remember the universal gas law: pV = nRT, or rearranged n/V = p/RT, so that the number of moles per unit of volume equals atmospheric pressure over temperature (R is the universal gas constant).  Since mass is equal to n * MM where MM is the molecular weight of your gas, density will equal to n/V * MM, and since n/V is constant, the density of a gas at a given temperature and pressure is directly proportional to the gas’ molecular weight.

BC

[BostonCard]

thanks for the explanations. I think the second part of the explanation for me is that the water molecules are not simply added to the air molecules in a given volume of dry air; at the same temperature they are in place of them so the overall density is lighter.
Whatever the explanation, I'm all for it as long as we hit many more home runs than them, with a higher density of baserunners when we hit 'em.

Remember the universal gas law: pV = nRT, or rearranged n/V = p/RT, so that the number of moles per unit of volume equals atmospheric pressure over temperature (R is the universal gas constant).  Since mass is equal to n * MM where MM is the molecular weight of your gas, density will equal to n/V * MM, and since n/V is constant, the density of a gas at a given temperature and pressure is directly proportional to the gas’ molecular weight.

BC