The atomic number decreases by 2.

The atomic number increases by 1.

The atomic number decreases by 1.

Both the atomic number and mass number remain unchanged.

An unstable neutron-to-proton ratio within the nucleus.

The nucleus becomes more stable, with a reduced mass and atomic number.

The process where unstable atomic nuclei release energy and particles to become more stable.

A particle consisting of two protons and two neutrons, equivalent to a helium nucleus ($mathrm{He}^{2+}$).

An electrically neutral particle with nearly zero mass, emitted in beta-plus decay.

A particle with the same mass as an electron but with a positive charge, also known as an antielectron ($e^{+}$ or $\beta^{+}$).

An electrically neutral particle with nearly zero mass, emitted in beta-minus decay.

A high-energy photon emitted by an excited nucleus during gamma decay ($gamma$).

Beta-minus: Neutron transforms into a proton, emits electron and antineutrino. | Beta-plus: Proton transforms into a neutron, emits positron and neutrino.

Alpha: Emission of a helium nucleus, changes mass and atomic number significantly. | Beta: Emission of an electron or positron, changes only atomic number.

Neutrinos: Emitted in beta-plus decay. | Antineutrinos: Emitted in beta-minus decay. Both are electrically neutral and have nearly zero mass.

Alpha particle: Consists of 2 protons and 2 neutrons, has mass and charge. | Gamma ray: Is a high-energy photon, massless and chargeless.

Electron: negatively charged particle emitted in beta-minus decay. | Positron: positively charged particle emitted in beta-plus decay.