Question

Write an expression for mass defect.

Hint:

The mass defect represents the mass lost when a nucleus is formed and is directly related to the binding energy of the nucleus.

Answer 1

Step 1: Defining mass defect.
Mass defect refers to the difference in mass between the nucleus of an atom and the sum of the masses of its individual nucleons (protons and neutrons). The mass defect is the amount of mass that has been converted into binding energy when the nucleus is formed.
Step 2: Expression for mass defect.
The mass defect \( \Delta m \) is given by the formula: \[ \Delta m = \left( \text{mass of protons and neutrons} \right) - \left( \text{mass of nucleus} \right) \] This difference is due to the energy released when the nucleus is formed, according to Einstein’s equation \( E = \Delta m c^2 \), where \( E \) is the binding energy and \( c \) is the speed of light.
Step 3: Conclusion.
Thus, the mass defect is the difference between the total mass of the nucleons and the mass of the nucleus.