Although a stable nucleus can exist indefinitely, the vast majority of nuclei are unstable. Radioactivity, or the spontaneous breakdown of a nucleus through the emission of radiation, is exhibited by an unstable nucleus.

The changes that occur in atomic nuclei are very different from chemical changes. Electrons are shared or transferred to produce compounds in chemical processes, while nuclei stay unaltered.

In nuclear processes, the roles are reversed: electrons play a significant role. Less frequently, nuclei undergo modifications that almost always result in the formation of new elements.

Nuclear reactions are frequently followed by a million-fold increase in energy. Energy changes in chemical processes are so significant that the associated changes in the mass are noticeable. Furthermore, nuclear reaction yields and rates are not affected by the pressure, temperature, and catalytic effects that influence.

Nucleons are the fundamental particles that make up the nucleus, protons, and neutrons. Each nucleus has its own unique composition, that is, precise quantities of protons and neutrons. A nuclide is one of the two kinds of nucleons.

Atoms having the typical amount of protons for a given element but with Isotopes are varying numbers of neutrons.

The majority of elements are found in nature as an isotope mixture For example, there are three naturally occurring isotopes of oxygen.

Mercury has seven, whereas tin has ten, the most of any element. As a result, each isotope of an element, element has a unique nuclide.

A nuclide is denoted by the notation Z A X, where X is the element symbol. The mass number, A, is the number of nucleons (the sum of protons and neutrons). The atomic number is Z. (the number of protons).

The mass number (A) minus the atomic number (Z) equals the number of neutrons (N) in a nucleus: N = A Z. The two naturally occurring stable isotopes of chlorine, for example, are:

• Nuclides can alternatively be identified by the element name followed by the mass number, such as chlorine-35 and chlorine-37.

• The isotopes of an element or its compounds are present in precise quantities that fluctuate only slightly in naturally occurring samples of the element or its compounds.

Antoine-Henri Becquerel, a French physicist, discovered by accident in 1896 that uranium crystals generate penetrating radiation capable of exposing a photographic plate.

Becquerel also discovered that radiation causes an electric discharge in the air, allowing him to measure its intensity.

In 1898, a young doctorate student called Marie Sklodowska Curie launched a search for additional minerals that behaved like uranium minerals based on Becquerel's discoveries. She discovered that thorium minerals produce radiation as well and that the strength of the radiation is related to the concentration of the element in the mineral rather than the formula of the mineral or combination.

Curie gave the emissions the term radioactivity and demonstrated that they are unaffected by temperature, pressure, or other physical and chemical conditions.

Curie and her husband, scientist Pierre Curie, completed months of laborious chemical work.

Pierre Curie demonstrated the presence of two additional elements in pitchblende, the main element.

Polonium (Po; Z = 84), the most metallic member of Group 6A, is a uranium ore (16), and the heaviest alkaline earth element, radium (Ra; Z = 88).

Curie then began with many tons of radium to get a quantifiable amount, as shown in the image above.

She labored tirelessly to extract uranium from pitchblende leftovers. She worked for four years to isolate 0.1 g of radium chloride, which she melted and evaporated.

Becquerel, the Curies, Paul Villard in France, and Ernest Rutherford and his colleagues in England researched the nature of radioactive emissions during the following few years. Rutherford and his colleague Frederick made an important discovery.

When radium decays, elements other than radium are produced, according to Soddy. They were founded in 1902, hypothesized that radioactive emissions cause the transformation of one element into another.

This explanation appeared to be a return to alchemy, and it was received with skepticism and ridicule. We now know that when a nuclide of one element decays, it emits another.

It emits radiation and generally transforms into a nuclide of a different element.