Find the energy equivalent of one atomic mass unit, first in Joules and then in MeV. Using this, express the mass defect of `""_(8)^(16)O` in `MeV//c^2`.

Explanation

`1 u = 1.6605 xx 10^(-27) kg`
To convert it into energy units, we multiply it by `c^2` and find that energy equivalent `= 1.6605 xx 10^(-27) xx (2.9979 xx 10^8)^2 kg m^2//s^2`
`= 1.4924 xx 10^(-10) J`
`= (1.4924 xx 10^(-10))/(1.602 xx 10^(-19)) eV`
`= 0.9315 xx 10^(9) eV`
`= 931.5 MeV`
or, `1 u = 931.5 MeV//c^2`
For `""_(8)^(16)O , " " Delta M = 0.13691 u = 0.13691 xx 931.5 MeV//c^2`
`= 127.5 MeV//c^2`
The energy needed to separate `""_(8)^(16)O` into its constituents is thus `127.5 MeV//c^2`.