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Glite Dictionary
mass defect

mass defect

7.4
The mass difference between a nucleus inside an atom and the total mass of its protons and neutrons
  • noun
  • /mæs dɪˈfɛkt/
  • Specialized
translation icon : defecto de masa
  • In nuclear physics, the mass defect is crucial for understanding the binding energy of atoms.

So we would expect the mass defect to follow a certain trend.

Examples

  • Hulthen dismissed the importance of their theoretical work as the basis for the energy calculation, arguing that it could have been done from the available data on mass defects without recourse to a nuclear model.

    Academic text (1997)

  • So we would expect the mass defect to follow a certain trend.

    MIT OpenCourseWare

  • The scientist calculated the mass defect to understand the nucleus's stability.

  • Researchers measured the mass defect to determine how much energy could be released in nuclear reactions.

Synonyms

mass deficiency
vsmass defect
  • Specialized
7.7

Amount of mass missing when protons and neutrons join and release energy

focuses only on the mass difference without stating its cause

Surface Forms

mass defect singular
mass defects plural

Morphology

mass + defect

The phrase combines the transparent noun 'mass' with 'defect' (which can be understood as a lack or shortcoming), so a learner who knows both words could plausibly infer a meaning like 'a shortage or missing amount of mass'. However, the expression has a specific technical meaning in physics (a precise quantitative difference between nuclear mass and the sum of constituent masses) and 'defect' can also mean 'flaw', so the exact technical sense is not fully predictable to a B1 learner without exposure.

Etymology

Mass defect comes from a simple image of a small amount of mass that is missing, with defect meaning a 'missing piece'. So it names the 'difference' between the mass of the atom's tiny center and the total mass of its parts, like protons and neutrons.