Question

Find the energy equivalent of one atomic mass unit first in joules and then in mev

Answer 1

I amu=1.66×1027 kg c = speed of light = 3×108 m/sE = mc2E= 1.66×1027×( 3×108)2E = 1.49×10−10 joule1 MeV= 1.6×10−13 JE = 1.49×10−101.6×10−13= 931.6 MeVO168mass no = 16energy for 16 amu = 16×931.6 = 14905.6 MeVmass defect = energyc2 = 14905.6 MeV/c2

Answer 2

14905.6 $MeVc^{-2}$ is Mass Defect

Explanation:

We know that 1 Atomic Mass Unit (amu) = $1.66 \times 10^{27$} kg

And Speed of Light, c = $3 \times 10^8\ ms^{-1}$

E = $mc^2$

or

E = $1.66 \times 10^2^7 \times (3 \times 10^8)^2$

E = $1.49 \times 10^{-10}$ joule

1 MeV = $1.66 \times 10^{-13}$ J

We know that,  

E = $\frac {1.49 \times 10^{-10}}{1.6 \times 10^{-13}}$

= 931.6 MeV

$O_{8}^{16}$

Mass number = 16

Energy for 16 amu = $16 \times 931.6$

= 14905.6 MeV

Mass Defect = $\frac {Energy}{c^2}$

= 14905.6 $MeVc^{-2}$