Question

What are the $\alpha$ and $\beta$ particles emitted from ${}_{90}{Th}^{228}{\to }_{83}{Bi}^{212}$

• A. Four alpha and one beta
• B. Three alpha and seven beta
• C. Eight alpha and one beta
• D. One alpha and four beta

Answer 1

The correct option is A Four alpha and one beta

${}_{90}T{h}^{228}{\to }_{83}B{i}^{212}+x_2{\alpha }^4+y_{-1}{\beta }^0$

$228=212+4x$

$4x=16$

$x=4$

Four ${}^{\prime }{\alpha }^{\prime }$ particles

$90=83+(4\times 2)-y$

$y=1$

one $\beta$ particle