Mass Defect


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Mass defect

The difference between the mass of an atom and the sum of the masses of its individual components in the free (unbound) state. The mass of an atom is always less than the total mass of its constituent particles; this means, according to Albert Einstein's well-known formula, that an energy of E = mc2 has been released in the process of combination, where m is the difference between the total mass of the constituent particles and the mass of the atom, and c is the velocity of light. The mass defect, when expressed in energy units, is called the binding energy, a term which is perhaps more commonly used. See Nuclear binding energy

Mass Defect

 

the difference between the mass of the atom of a particular isotope, expressed in atomic mass units, and the mass number, which is equal to the number of nucleons in the nucleus of that isotope. The mass defect is associated with the binding energy of the nucleons in the nucleus; it characterizes the stability of the particular nucleus. Sometimes the mass defect related to a single nucleon is used; this is called the packing fraction.

mass defect

[′mas ′dē‚fekt]
(nuclear physics)
The difference between the mass of an atom and the sum of the masses of its individual components in the free (unbound) state.
References in periodicals archive ?
MMDF improves upon the MDF method by allowing the user to combine the results from up to six different mass defect filters.
The samples were analysed using a Thermo Scientific LTQ Orbitrap XL with an HCD collision cell; the application of mass defect filters was achieved by using the Thermo Scientific MetWorks software package (Figure 2).
The background matrix ions remained because by using only a single MDF to capture all of the metabolites, a relatively wide mass defect range had to be used.
High Resolution LC-MS Based Mass Defect Filter Approach: Basic Concept and Application in Metabolite Detection," in R.