OCR Physics Nuclear Physics Revision Notes

• 1The nucleus is composed of protons and neutrons, collectively known as nucleons.
• 2Radioactive decay occurs when an unstable nucleus loses energy by emitting radiation.
• 3Nuclear fission is the process of splitting a heavy nucleus into lighter nuclei, releasing energy.
• 4Nuclear fusion is the process of combining light nuclei to form a heavier nucleus, also releasing energy.
• 5The strong nuclear force is the fundamental force that holds nucleons together in the nucleus.

Nuclear physics studies the tiny parts of atoms called nuclei, which are made up of protons and neutrons. Sometimes these nuclei are unstable and can release energy in the form of radiation, which is called radioactivity. There are two main processes in nuclear physics: fission, where a heavy nucleus splits apart, and fusion, where light nuclei combine. Both processes release a lot of energy and are important for things like nuclear power and stars.