Structure Of Atom

In a β-decay, a nucleus undergoes a transformation in which a neutron is converted into a proton, an electron (also known as a β-minus particle, denoted as -1e0), and an antineutrino (v). This results in the increase of the atomic number (Z) by one unit (hence the "+1" in Z + 1YA), while the mass number (A) remains the same.

A nucleus is represented by the symbol has Z protons and A – Z neutrons.