Find the kinetic energy of the alpha particle emitted in the 226 Ra 222 Rn + 4He. alpha decay process

• Alpha decay is one of the processes in which an unstable nucleus decays into a stable one. In alpha decay, the unstable nucleus disintegrates into a lighter nucleus and an alpha particle (nucleus of helium) is released.

• The following reaction takes place in alpha decay.

$\boxed{{}_{\mathbf{\text{Z}}}{}^{\mathbf{\text{A}}}\mathbf{\text{X}}_{\mathbf{\text{N}}}\mathbf{\to }{}_{\mathbf{\text{Z}}\mathbf{-}\mathbf{2}}{}^{\mathbf{\text{A}}\mathbf{-}\mathbf{4}}\mathbf{\text{X'}}_{\mathbf{\text{N}}\mathbf{-}\mathbf{2}}\mathbf{+}{}_{\mathbf{2}}{}^{\mathbf{4}}\mathbf{\text{He}}_{\mathbf{2}}}$

Here X and X' represent different nuclei.

• The kinetic energy of the alpha particle released is given by,

$\boxed{{\mathbf{K}}_{\mathbf{\alpha }}\mathbf{=}\left(\frac{A-4}{A}\right)\mathbf{Q}}$

Here A is the atomic number of the parent nucleus and Q is the energy released in the reaction.