Skip to main content

Mass Defect and Nuclear Binding Energy

This video presents the same text shown beside it, spoken and on screen. It adds nothing the text does not say.

State

A nucleus's mass defect is the gap between its particles' summed mass and measured mass; mass-energy equivalence converts that missing mass into binding energy.

Show

A helium-4 nucleus measures slightly less than its separate protons and neutrons, the missing mass accounting for binding energy.

Watch for

Mass-energy equivalence is a defining conversion, not a revisable measurement — the mass defect varies between nuclides.