Question

A nucleus with mass number 220 initially at rest emits an $\alpha$- particle. If Q value of reaction is 5 .5b MeV. Calculate the kinetic energy of the $\alpha$ particle

• A. 4.4 MeV
• B. 5.4MeV
• C. 5.6 v
• D. 6.5 MeV

Answer 1

Answer: (B)

5.4MeV

$\begin{array}{c}k\cdot E\text{of}\alpha \text{-particle}=\left[\frac{A}{A+4}\right]Q\\ A\to \text{Mass number}\left(220\right)\\ Q\to \text{Energy difference}\left(5.5\text{Mev}\right)\\ k.E=\left[\frac{220}{224}\right]\left(5.5\right)=5.406MeV\end{array}$