Group Displacement Law

It was observed that when an a-particle is lost, a new element with an atomic number less by 2 and a mass number less by 4 is produced. When the b-particle is lost, a new element with an atomic number larger than one is formed. The parent element emitting an or b-particle is referred to as the parent element, and the newly generated element is thus referred to as the daughter element.

Group Displacement Law

Fazan, Russel, and Soddy summarised the effects of α-particle and β-particle change in the Group Displacement Law, which states that “the α-particle emission from the nucleus of a radioactive substance (Parent element) results in the formation of a new element (daughter element) having atomic mass less by four units and is displaced two groups to the left of its parent element in the periodic table while β-particle emission results in the formation of a new element having same atomic mass but is displaced one group to the right of its parent element in the periodic table”.

Example-

84Po215— – α —–> 82Pb211 — – β —–> 83Bi211 — – β —–> 84Po211

90Th232 — – α —–> 88Ra228 — – β —–> 89Ac228 — – β —–> 90Th228

Group Displacement Law Radioactivity

In radiochemistry and nuclear physics, the law of radioactive displacements, also known as Fajan’s and Soddy’s law, is a rule that governs the transformation of elements during radioactive decay. It was named after Frederick Soddy and Kazimierz Fajans. Both arrived at it at about the same time in the year 1913.

Radioactive elements have unstable atoms. When a radioactive element’s atom disintegrates, a whole new element is created. Chemically and radioactively, the new element is completely unique. The dissolving material is known as the parent element, and the disintegrated product is known as the daughter element. Soddy and Fajan investigated the breakdown of radioactive elements’ consecutive product components and came to the following conclusions:

• Alpha-Emission

The nucleus of a helium atom with atomic number 2 and atomic weight 4 is known as an a-particle. It is symbolised by 2He4. As a result, when a radioactive parent atom (X) emits α-particles, its atomic number is lowered by two and its atomic weight is reduced by four. As a result, the daughter element is two groups below the parent element in the periodic table. The a-emission process may be stated as: ZXA→Z−2YA−4+(α−particle)2He4.

• Beta-Emission 

β-particle is an electron which is denoted by −1β0. The atomic number of a β-particle released from a parent atom (X) grows by one while the atomic weight remains static. As a result, the daughter element (Y) occupies a position in the periodic table one group higher. As a result, the β-emission process may be stated as ZXA→Z+1YA+−1β0+v−.

Here v− is a fundamental particle called antineutrino and is massless and chargeless.
Example 90Th228→89Ac228+−1b0+v−

• Gamma-Emission 

The emission of γ -ray by a radioactive atom has no effect on its atomic number or weight. As a result, its position in the periodic table stays unchanged. γ -radiation is accompanied by either α or β-emission in natural radioactivity.

Radioactivity

Because of the energy imbalance within the nucleus, atoms with unstable nuclei are continually altering. The radioactive nucleus, which is unstable, will emit energy in some form. The release of energy or the ejection of matter caused by changes in the nucleus of an atom is known as radioactivity.

Radioisotope

Isotopes are varieties of an element with different numbers of neutrons despite having the same number of protons. Isotopes are a type of variation. Because protons with similar charges resist each other, these forces are constantly attempting to push the atom’s nucleus apart. The binding energy is the force that holds the nucleus together.

Most elements want to have nearly the same number of protons and neutrons since this is the most stable configuration. The binding energy of stable atoms is strong enough to hold protons and neutrons together. Even if an atom gains one or two more neutrons, it may remain stable. Each additional neutron, on the other hand, may throw the atom’s balance off and lead it to become unstable. To achieve a balanced state in an unstable atom, the nucleus adjusts its configuration by emitting matter of energy. It is believed to be radioactive because the unstable nucleus emits radiation as it changes. Radioisotopes are isotopes that are radioactive.

Conclusion

When an a-particle is lost, a new element with an atomic number less by 2 and a mass number less by 4 is produced, according to Soddy, Fajans, and Russell (1911-1913). When the b-particle is lost, a new element with an atomic number larger than one is formed. The element that emits the a or b-particle is referred to as the parent element, and the newly produced element is referred to as the daughter element.