Question

Question #0a3ea

Answer 1

`1.51*10^24` atoms

Explanation:

1 mole of a molecule contains Avogadro's number of molecules.

Where,
`"Avogadro's number "= 6.02*10^23`

So one mole of `CH_4` contains `6.02*10^23` molecules of `CH_4`

Half a mole would contain half the amount that a mole contain,

In 0.5 mole of `CH_4`, there is `(6.02*10^23)/2=3.01*10^23`

But one molecule of `CH_4` contains 5 atoms (1 atom of carbon and 4 atoms of Hydrogen).

So number of atoms in 0.5 mole of `CH_4` is equal to number of molecules in 0.5 mol multiplied by 5.
`"number of atoms in 0.5 mole of CH_4"= "5⋅number of molecules in 0.5 mol" = 5*3.01*10^23=15.05*10^23=1.505*10^24≈1.51*10^24`

Hope that this will help. :)