The wavelength of a photon needed to remove a proton from a nucleus which is bound to the nucleus with 1MeV energy is nearly

Options

A. 1.2nm
B. `1.2 xx 10^(-3)nm`
C. `1.2 xx 10^(-6)nm`
D. `1.2xx 10nm`

Answer

B

Explanation

Energy of the photon must be equal to the binding energy of proton So, energy of photn = 1MeV `=10^(6) xx 1.6 xx 10^(-19)J`
`lamda= (hc)/(E )= (6.63 xx 10^(-34) xx 3 xx 10^(8))/(1.6 xx 10^(-13))= (6.63 x 3)/(1.60)xx 10^(-26+13)= (19.89)/(160) xx 10^(-13) = 12.4 xx 10^(-13) = 1.24 xx 10^(1) xx 10^(-13)`
`=1.24 xx 10^(-9) xx 10^(-3)= 1.24 xx 10^(-3)nm`