The value of one microcurie $=$ $.......$ disintegrations / second

After the emission of a $\beta$-particle followed by an $\alpha$-particle from ${ }_{83}^{214} Bi$,the number of neutrons in the resulting atom is:

Loss of a beta particle is equivalent to:

In the following nuclear reaction,identify $x$: $_{29}Cu^{64} \to _{28}Ni^{64} + x$

$A$ radioisotope will not emit

The $_{88}Ra^{226}$ is