Practicing Success
In the nuclear reaction ${ }_{85} X^{297} \rightarrow Y+4 \alpha, Y$ is |
${ }_{76} Y^{287}$ ${ }_{77} Y^{285}$ ${ }_{77} Y^{281}$ ${ }_{77} Y^{289}$ |
${ }_{77} Y^{281}$ |
${ }_{85} X^{297} \rightarrow{}_{77} Y^{281}+4\left({ }_2 H e^4\right)$ |