Elements one mole

One mole of any gas at STP occupies 22.4 L. How large is that It is the volume of a cube that is 28.2 cm on each edge. Each such volume contains 6.02 X 10 atoms of a gaseous element or 6.02 x 10 molecules of a molecular element or compound, but the mass of 1 mol is different for each element. One mole of helium floats because its mass is less than the mass of 22.4 L of air. 

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