Some radioactive nucleus may emit
Only one $\alpha ,\;\beta $ or $\gamma $ at a time
All the three $\alpha ,\;\beta $ and $\gamma $ one after another
All the three $\alpha ,\;\beta $ and $\gamma $ simultaneously
Only $\alpha $ and $\beta $ simultaneously
An element $A$ decays into element $C$ by a two step process :
$A \to B + {\;_2}H{e^4}$
$B \to C + \;2{e^ - }$
Then
A nucleus $_n{X^m}$emits one $\alpha $ and one $\beta $ particles. The resulting nucleus is
On the bombardment of neutron with Boron. $\alpha$-particle is emitted and product nuclei formed is
When a $_4B{e^9}$ atom is bombarded with $\alpha - $ particles, one of the product of nuclear transmutation is $_6{C^{12}}$. The other is
${ }_{92}^{235} U$ atom disintegrates to ${ }_{82}^{207} Pb$ with a half-life of $10^9 yr$. In the process, it emits $7 \alpha$ particles and $n \beta^{-}$particles. Here, $n$ is