Respuesta :

The correct answer is helium.
For Neon (Ne), the atomic mass is 10 daltons, so the molar mass is 10
grams. This means that one mole (Avogadro's number of particles, 6.02
x 10^23) has a mass of 10 grams. Hydrogen, with an atomic mass of
1 dalton for it's single proton, the molar mass would be 1 gram. With
Neon, the speed of the individual Neon atoms is
proportional to 1 / sqrt(10). So it is helium.