Question

5. Explain why?
(a) "The number of atoms in a certain volume of
hydrogen is twice the number of atoms in the same
volume of helium at the same temperature and
pressure."​

Answer 1

cause helium is comprised of 2 hydrogen atoms

while hydrogen is just one hydrogen atom.

Answer 2

Answer:

(a) This is due to Avogadros Law which states Equal volumes of all gases under similar conditions of temperature and pressure contain the same number of molecules.

Now volume of hydrogen gas =volume of helium gas

n molecules of hydrogen =n molecules of helium gas

nH2=nHe

1 mol. of hydrogen has 2 atoms of hydrogen and I molecule of helium has 1 atom of helium

Therefore 2H=He

Therefore atoms in hydrogen is double the atoms of helium.