https://en.wikipedia.org/wiki/Nuclear_isomer https://en.wikipedia.org/wiki/Nuclear_isomer In some cases, one configuration of the nucleus is football-shaped, a

https://en.wikipedia.org/wiki/Nuclear_isomer https://en.wikipedia.org/wiki/Nuclear_isomer In some cases, one configuration of the nucleus is football-shaped, and there's an energy difference between that and the round shape. In other cases, a set of two protons and two neutrons will be jolted loose from the rest of the nucleus, and sort of orbit around it.