Weak force

In physics, the weak force or weak interaction is a fundamental force in the universe that is required to explain radioactive decay. Ironically, this force is not entirely weak but rather acts at such a short range it was originally called contact, though it is a much weaker force than both the strong force and electromagnetism

The most well known example is beta decay or beta radiation

For example 𝛽 decay

A Feynmann diagram showing a neutron at the bottom(udd) decaying into a proton (udu) via a W- particle to produce an electron (e-) and anti neutrino 𝜈e. image: wikipedia

neutron → proton + electron + anti neutrino