Question

Calculate the average atomic mass of hydrogen using the following data
Isotope % Natural abundance Molar mass
`.^(1)H 99.985 1`
`.^(2)H 0.015 2`

Answer 1

Many naturally occuring elements exist as more than one isotope when we take into account the existence of these isotopes and their relative abundance (per cent occuranece), the average atomic mass of the element can be calcualted as
{(Natural abundance of `.^(H)xx` molar mass of `.^(2)H`)}+
Average atomic mass `=(("Natural abundance of" `.^(2)Hxx` "molar mass of" .^(2)H))/(100)`
`=(99.985xx1+0.015xx2)/(100)`
`=(99.985+0.030)/(!00)=(100.015)/(100)=1.00015u`