Question

`A compound known as deuterium oxide, or "heavy water" is sometimes used in nuclear research. It is water, but each hydrogen atom in a "heavy water" molecule has a neutron in the nucleus in addition to the normal proton. So, what would be the percent hydrogen (by mass) in a "heavy water" molecule?

Answer 1

20%

Step-by-step explanation:

molecular formula of deuterium oxide, or "heavy water" is
`D_2O`

molecular weight of D2= 4.028204 g/mol

molecular weight of oxygen= 16 g/mol

therefore, molecular weight of water = 20.028204 g/mol

therefore, the percent hydrogen (by mass) in a "heavy water" molecule

=(molecular weight of D2/molecular weight of water)

`= (4)/(20.028204)*100`

= 20%