BUILDING ELEMENTS. “Then we build our way up through the periodic table creating heavier and heavier things through different types of processes. In some cases we just add a proton and it grows. In other cases we add a bunch of neutrons and these neutrons decide to flip what they are between protons decaying through a process called the reverse beta decay.”
http://www.astronomycast.com/transcripts/AstroCast-080922_transcript.pdf