What is the fraction of the mass of water due to neutrons?

Explanation

In water molecule `(H_(2)O)`, number of neutrons =[(number of neutrons in H) `xx2+` (number of neutrons in O)]
`=0 xx 2+8=8` (as number of neutrons in H=O)
`=0 xx 2+8 = 8` (as number of neutrons in H) `xx2+` (number of neutrons in H=O)
Molar mass of water =`8 xx 1.00893 =8.07` (`therefore` Mass of one neutron `=1.008934)`
Molar mass of water = `1.008 xx 2 + 16.0=18.016u`
`therefore` Fraction of mass due to neutrons = `("mass of total neutrons in water" xx 100)/("molar mass of water")`
`(8.07)/(18.016) xx 100 ~~ 44.8%`