How does the weak force change one element into another?

The weak nuclear force is responsible for radioactive processes where particles inside nuclei transform. In beta minus decay, a neutron turns into a proton, emitting an electron and an antineutrino. In beta plus decay, a proton can turn into a neutron, emitting a positron and a neutrino. This force is essential in nuclear reactions, including some processes inside the Sun. It was unified with electromagnetism in the electroweak theory, developed in the 1960s by Sheldon Glashow, Abdus Salam, and Steven Weinberg.