If $_{92}U^{238} \to _{Z}X^{A} + _{2}He^{4}$,then $Z$ and $A$ will be ..........

When ${}_{92}U^{238}$ changes into ${}_{82}Pb^{206}$,the number of $\alpha$ and $\beta^-$ particles emitted are:

The $Q$-value of the decay ${ }_{11}^{22} Na \rightarrow{ }_{10}^{22} Ne + e ^{+}+v$ is

In the following nuclear reaction,$x$ stands for: $n \rightarrow p + e^{-} + x$

In the given reaction ${}_{Z}^{A}X \to {}_{Z+1}^{A}Y \to {}_{Z-1}^{A-4}K \to {}_{Z-1}^{A-4}K$,the radioactive radiations emitted in the sequence are:

Before the neutrino hypothesis,the beta decay process was thought to be the transition $n \to p + e^-$. If this were true,show that if the neutron was at rest,the proton and electron would emerge with fixed energies and calculate them. Experimentally,the electron energy was found to have a large range.