Question

Assume that a neutron breaks into a proton and an electron. The energy released during this process is :
(Mass of neutron $= 1.6725 × 10^{-27}\, kg$,
Mass of proton $= 1.6725 × 10^{-27}\, kg$,
Mass of electron $= 9 × 10^{-31}\, kg$ )

• A. $0.51\, MeV$
• B. $7.10\, MeV$
• C. $6.30\, MeV$
• D. $5.4\, MeV$

Answer 1

Answer: (A)

$_{0}n^{1} \rightarrow _{1}H^{1}+_{-1}e^{0}+\bar{v}+Q$
$\Delta m=m_{n}-m_{\alpha}-m_{e}$
$= \left(1.6725 × 10^{-27} - 1.6725 × 10^{-27} - 9 × 10^{-31}\right) kg$
$=-9\times10^{-31}\times\left(3\times10^{8}\right)^{2}$
Energy $= 9× 10^{-31} × \left(3 × 10^{8}\right)^{2}$
$= 0.511\, MeV$
Which is nearly equal to $0.73 \,Mev$
but as energy will be required.
since mass is increasing
so answer $= -0.511\, Mev$