What is the alpha decay equation?

##""_Z^AX->""_(Z-2)^(A-4)Y+""_2^4He+Q##

An Alpha Particle consists of two protons and two neutrons. Thus when occurs there occurs a reduction in the atomic no by 2 and mass no by 4 in the parent element to form the daughter element. This can be represented by the following generalised formula

##""_Z^AX->""_(Z-2)^(A-4)Y+""_2^4He+Q##

where X= parent element Z= atomic no A= mass no Q= energy released Y= daughter element