Respuesta :

Avogadro’s constant tells us the number of atoms in a mole of any substance: 6.022x10^23. A mole of water, oxygen, sodium - they all have this many atoms in a 1 mole sample.

A 0.5 mole sample of helium gas would contain 0.5 x (6.022 x 10^23) atoms, or 3.011 x 10^23 atoms. Still a big amount.

Answer :  The total number of molecules in 0.5 mole of sample of He gas are, [tex]3.011\times 10^{23}[/tex]

Explanation : Given,

Moles of sample of He gas = 0.5 mole

As we know that,

1 mole of gas contains [tex]6.022\times 10^{23}[/tex] number of molecules of gas

As, 1 mole of He gas contains [tex]6.022\times 10^{23}[/tex] number of molecules of He gas

So, 0.5 mole of He gas contains [tex]0.5\times (6.022\times 10^{23})=3.011\times 10^{23}[/tex] number of molecules of He gas

Therefore, the total number of molecules in 0.5 mole of sample of He gas are, [tex]3.011\times 10^{23}[/tex]