7.3 Atomic And Nuclear Physics

The difference between the mass of the nucleus and the sum of the masses of its individual nucleons divided by the number of nucleons is known as the mass defect. This is because the mass of the nucleus is always less than the sum of its individual nucleons due to the release of energy during the formation of the nucleus. The binding energy per nucleon, on the other hand, is the energy required to separate one nucleon from the nucleus. It is a measure of the stability of the nucleus and is obtained by dividing the total binding energy of the nucleus by the number of nucleons. Therefore, the correct answer is binding energy per nucleon.

The energy required to separate a nucleus into its component nucleons is known as the binding energy. This energy is the result of the strong nuclear force that holds the nucleons together within the nucleus. The binding energy is essentially the amount of energy that would need to be supplied to overcome this force and separate the nucleons. Therefore, the correct answer is binding energy.

The correct answer is fusion. Fusion is the process in which two or more atomic nuclei come together to form a larger nucleus, releasing a large amount of energy in the process. This is the process that powers the Sun, where hydrogen nuclei combine to form helium, releasing a tremendous amount of energy in the form of light and heat. Fission, radioactivity, and ionization are not the sources of the Sun's energy.

When a neutron is captured by a nucleus, it combines with a proton in the nucleus to form a new nucleus. The proton number remains unchanged because no protons are gained or lost. However, since a neutron is added, the nucleon number increases by 1. This is because the nucleon number includes both protons and neutrons, so adding a neutron increases the total number of nucleons in the nucleus.

The unified mass unit is defined as a twelfth of the mass of one neutral atom of C12. This means that one unified mass unit is equal to 1/12th of the mass of a single neutral C12 atom.

The mass defect refers to the difference in mass between the total mass of the reactants before a nuclear interaction and the total mass of the products after the interaction. It is caused by the conversion of a small amount of mass into energy according to Einstein's equation, E=mc^2. Therefore, the mass defect is a measure of the amount of energy released during a nuclear reaction.

In a fission chain reaction, neutrons from one fission reaction cause further fission reactions. When a nucleus undergoes fission, it releases a few neutrons along with a large amount of energy. These neutrons can then collide with other nuclei, causing them to undergo fission as well. This releases more neutrons and continues the chain reaction. The release of energy in each fission reaction is what sustains the chain reaction and allows it to continue.

The difference between the mass of the nucleus and the sum of the masses of its individual nucleons is known as the binding energy. Binding energy represents the energy required to separate the nucleons and is a measure of the stability of the nucleus. This energy is released when nucleons come together to form a nucleus, and it is responsible for holding the nucleus together. The binding energy per nucleon, which is the binding energy divided by the number of nucleons, is a useful measure to compare the stability of different nuclei.