(d) $n_{\alpha} = \frac{A - A'}{4} = \frac{200 - 168}{4} = 8$ $n_{\beta} = 2n_{a} - Z + Z^{'} = 2 \times 8 - 90 + 80 = 6$
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.