Answer: [tex]_{82}^{204}\textrm {Pb}[/tex]
Explanation:-
Alpha Decay: In this process, a heavier nuclei decays into lighter nuclei by releasing alpha particle or a helium nucleus.The atomic number gets reduced by 2 units and the mass number is reduced by 4 units.
General representation of an element is given as:[tex]_Z^A\textrm{X}[/tex]
where,
Z represents Atomic number
A represents Mass number
X represents the symbol of an element
The chemical equation for a alpha decay is represented as:
[tex]_Z^A\textrm{X}\rightarrow _{Z-2}^{A-4}+_2^4\alpha[/tex]
[tex]_{84}^{208}\textrm{Po}\rightarrow _{84-2}^{208-4}\textrm {Y}+_2^4\textrm{He}[/tex]
[tex]_{84}^{208}\textrm{Po}\rightarrow _{82}^{204}\textrm {Pb}+_2^4\textrm{He}[/tex]
