What is the particle released during alpha decay?

During alpha decay, the particle that is released is the alpha particle, which is composed of two protons and two neutrons. This configuration is identical to the nucleus of a helium atom, hence its notation as 4/2 He, where 4 is the atomic mass (the total number of protons and neutrons) and 2 is the atomic number (representing the number of protons).

Alpha decay occurs in heavier elements where the nucleus is unstable due to an excess of protons and neutrons. When the nucleus emits an alpha particle, it transforms into a different element that is two atomic numbers lower on the periodic table and has a mass number reduced by four. This process helps stabilize the original atom.

The other options represent different particles: 0/-1 e, a beta particle; γ, a gamma photon; and 12/6 C, the notation for carbon-12, which is a stable isotope of carbon. Therefore, the release of an alpha particle as 4/2 He is definitive to alpha decay, making it the correct answer.