2006-09-19 11:52:28 · 9 answers · asked by ~*CURLYSUE*~ 1 in Science & Mathematics ➔ Chemistry
Hydrogen = 1 proton + 1 electron
Helium = 2 protons + 2 neutrons + 2 electrons
Therefore, Hydrogen is significantly lighter than helium.
The density of either depends on how much of each is packed into a specific space. This can vary greatly depending on the circumstances. At certain densities, helium and hydrogen can become liquid and even solid (frozen).
2006-09-19 13:01:56 · answer #1 · answered by Todd 3 · 0⤊ 0⤋
Hydrogen has 1 electron helium has 2 electron the bigger the atom the more it weighs.
2006-09-19 11:58:01 · answer #2 · answered by JOHNNIE B 7 · 0⤊ 0⤋
Because Heliums mass doubles hydrogens.
2006-09-19 12:49:15 · answer #3 · answered by universalsoul 2 · 0⤊ 1⤋
andreicnx has it correct, but let me give a little more detail.
The density of He gas is approx. twice that of H gas at standard temperature and pressure. Why?
He has 2 protons and 2 neutrons or a mass of 4 AMU. (Electron are so light that you can ignore them.) H has only one proton for a mass of 1 AMU. But... the H atoms always bind together in pairs. So as andreicnx says, the molecule is H2 or two H atoms with a mass of 2 AMU.
So we have twice the molecular mass with He compared to H2, hence twice the gas density.
2006-09-19 13:34:41 · answer #4 · answered by Tom H 4 · 1⤊ 0⤋
Hydrogen isn't less dense than helium, it is lighter because there are less protons, neutrons and electrons, half actually.
2006-09-19 11:57:09 · answer #5 · answered by OobyDooby 4 · 0⤊ 1⤋
Atoms move faster
2006-09-19 11:53:32 · answer #6 · answered by wingnutrosie 3 · 0⤊ 1⤋
atomic mass of H2 is 2, and atomic mass of He is 4, therefor their densities are 2/22.4 g/dm3 and 4/22.4 g/dm3.
2006-09-19 12:09:01 · answer #7 · answered by andreicnx 3 · 1⤊ 0⤋
It's atom has only one electron.
2006-09-19 12:02:00 · answer #8 · answered by Jay 6 · 0⤊ 0⤋
Why don't you take a chem class and find out lots you don't know?
2006-09-19 12:01:04 · answer #9 · answered by snvffy 7 · 0⤊ 1⤋