How many he atoms will fit in 1 meter?

Answer 1

Assuming that you are talking about cubic meter (volume) then you can use PV = nRT, where P is pressure, V is volume, n is number of moles of the substance, R is the ideal gas constant, and T is absolute temperature. See the related link below. The units of R chosen will depend on what units are used for pressure and volume. You can rearrange and solve for number of moles, then multiply this by 6.023 x 10²³ to get number of atoms (Helium is a noble gas so it will have 1 atom per molecule).