Example Showing Mass defect and Binding energy
Nuclear binding energy is the energy required to split a nucleus of an atom into its component parts.
The component parts are neutrons and protons, which are collectively called nucleons. The binding energy of nuclei is always a positive number, since all nuclei require net energy to separate them into individual protons and neutrons. Thus, the mass of an atom's nucleus is always less than the sum of the individual masses of the constituent protons and neutrons when separated. This notable difference is a measure of the nuclear binding energy, which is a result of forces that hold the nucleus together. Because these forces result in the removal of energy when the nucleus is formed, and this energy has mass, mass is removed from the total mass of the original particles, and the mass is missing in the resulting nucleus. This missing mass is known as the mass defect, and represents the energy released when the nucleus is formed.
Mass Defect in Hydrogen
Mass Defect:
The mass defect of a nucleus represents the mass of the energy of binding of the nucleus, and is the difference between the mass
of a nucleus and the sum of the masses of the nucleons of which it is composed. Determining the relevant nuclear binding energy
encompasses three steps of calculation, which involves the creation of mass defect by removing the mass as released energy:
- Determining the mass defect
- Conversion of mass defect into energy
- Expressing nuclear binding energy as energy per mole of atoms, or as energy per nucleon.
Mass Defect – Formula
Mass defect is defined as the difference between the mass of a nucleus, and the sum of the masses of the nucleons of which it is composed. The mass defect is determined by calculating three quantities. These are: the actual mass of the nucleus, the composition of the nucleus (number of protons and of neutrons) and the summed masses of that many individual protons and neutrons. This is then followed by converting the mass defect into energy, according to the equation E=mc2. This quantity is the nuclear binding energy, however it must be expressed as energy per mole of atoms or as energy per nucleon.