Fission and fusion

Science

Definition

Nuclear fission is the splitting of a heavy atomic nucleus into smaller nuclei, releasing energy. Nuclear fusion is the combining of light nuclei into a heavier nucleus, also releasing energy. Both processes convert a small amount of mass into enormous energy according to E = mc².

Examples

  • Nuclear power plants use fission of uranium-235
  • The Sun produces energy through fusion of hydrogen into helium
  • Hydrogen bombs use fusion reactions
Key Fact

E = mc²; both fission and fusion convert mass to energy

Related Terms

Nuclear energy Nuclear physics Radioactive decay Subatomic particles

Study This Concept

Practice fission and fusion with free review games in these units:

Chemistry Unit 9: Nuclear Chemistry