Question

A neutron and a proton combine to form a nucleus. Why does the mass of the

nucleus differ from the sum of the masses of the individual nucleons?
A. The nucleus has less mass, because matter is converted into
binding energy.
B. The nucleus has more mass, because binding energy is converted
into matter.
C. The nucleus has less mass, because binding energy is converted
into matter.
D. The nucleus has more mass, because matter is converted into
binding energy.

Answer 1

A. The nucleus has less mass, because matter is converted into binding energy.

Step-by-step explanation:

A neutron and a proton combine to form a nucleus. The reason why the mass of the nucleus differs from the sum of the masses of the individual nucleons is:

A. The nucleus has less mass, because matter is converted into binding energy.

The process of combining a neutron and a proton to form a nucleus releases a tremendous amount of energy, called binding energy. According to Einstein's theory of relativity, this energy is equivalent to a certain amount of mass, given by the famous equation E=mc², where E is energy, m is mass, and c is the speed of light. The mass of the nucleus is therefore slightly less than the sum of the masses of the individual nucleons because some of the mass has been converted into binding energy. This effect is known as mass defect, and it is responsible for the stability of atomic nuclei. Therefore, the correct answer is A.