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Nuclear Energy - Binding Energy in Nuclei.. Physics

Nuclear Energy

Before 1911, it was believed that the atom was composed of a homogeneous mixture of protons and electrons. However, physicist Ernest Rutherford later confirmed that protons carrying positive charges are located in the center of the atom inside a small pole called the nucleus, and electrons carrying negative charges revolve around it. It is known that the charge of the electron is equal to the charge of the proton and opposite to it at the same time, and that the atom being electrically neutral makes it have a number of electrons equal to the number of protons in the nucleus. This number is called the atomic number Y. It is also known that the proton is 1836 times heavier than the electron, which makes the mass of the atom confined to its nucleus, which is characterized by its small size compared to the size of the entire atom.

Except for the hydrogen atom, the nuclei of all atoms contain another particle called a neutron, which was discovered in 1932 and was found to have a mass equal to the mass of the proton itself. Both protons and neutrons are known as nuclei, and they are bound together inside the nucleus of the atom. Isotopes are atoms that have an identical number of protons and a different number of neutrons. For example, hydrogen is an element with only one proton in its nucleus. It has two isotopes: deuterium (one proton and one neutron) and tritium (one proton and two neutrons). Since the chemical properties of an element are linked to the number of its electrons and thus the number of its protons, increasing the number of neutrons in the nucleus has no effect on these properties.

The neutron inside the nucleus is bound, in other words, stable. Outside it, it loses this stability and becomes susceptible to decay within 12 minutes, after which it turns into a proton, an electron, and another particle called a neutrino. This same decay occurs inside an unstable radioactive atom. The neutrino has no charge at all, and it has no mass in its stagnant state.

The length of the nucleus beam of the atom ranges between 2 × 10-15 and 19 × 10-12 meters, and the nuclei are packed tightly together. Although there are repulsive forces between protons, resulting from their similar charges, there is a greater force that only works in a short range and is called the exchange force between nuclei, and its mission is to link the nuclei to each other. It is believed that the nuclei exchange another particle called a meson within a short period not exceeding 3410 seconds. This exchange is responsible for the existence of nuclear forces. It is worth noting that the meson M or pion is a particle with a charge that is either positive or negative or zero. It is unstable, while the meson or muon is the result of the decay of the pion itself. These two types of particles were discovered in cosmic rays.

Binding energy in nuclei

Despite the small size of nuclear particles, it is possible to know their mass with great accuracy. The relative atomic mass (or atomic weight), of an element, is the amount of mass of its atom compared to an isotope of carbon that contains twelve nuclei and is called carbon-12, and its mass is defined as being equal to 12 atomic mass units (ATU). Since each element has a certain number of isotopes, and the atomic mass is the average mass of the isotopes according to their proportion in the substance, it is certain that the atomic mass cannot be an integer. If we consider both the proton and the neutron to be similar and each of them represents a unit of atomic mass, then the mass number of an isotope is the closest integer to its atomic weight. The isotope is usually written as y, where a represents the atomic number and w - y represents the number of neutrons in it. Accordingly, carbon-12 can be written as 12/6K or 12K. The mass of a proton is about 1.00782 ATU. The mass of the neutron is 1.00867 units. However, the mass of the nucleus is not equal to the sum of the masses of its contents, but is slightly less than it. The atomic mass of the deuterium atom is 2.01410 and 0 k.d. although it contains only a proton and a neutron. This means a loss of 0.00279 units. It is worth noting that this loss of mass is explained by Einstein's principle of mass-energy equivalence. It states that each mass m represents, except for the energy equal to F = m H2, where H represents the speed of light in the nucleus of the hydrogen atom, the apparent loss observed in all nuclei represents all the energy generated by the union of nuclei with each other during the formation of the complete nucleus, and is called the binding energy Q, which is equal to the difference between the sum of the masses of the separate nuclei and the atomic mass. It must be noted that in order to split the nucleus, it must be supplied with this amount of energy (except in the case of natural radioactive decay).

(Binding energy of each nucleus relative to the mass number of the elements)