Bismuth-210 \(\left( {_{\;83}^{210}{\text{Bi}}} \right)\) is a radioactive isotope that decays as follows.

\[_{\;83}^{210}{\text{Bi}}\xrightarrow{{{\beta ^ - }}}{\text{X}}\xrightarrow{\alpha }{\text{Y}}\]

What are the mass number and proton number of Y?

B