Radioactivity

Radioactivity was discovered in 1896 by scientists Henri Becquerel and Marie Curie while working with phosphorescent substances. These materials glow in the dark after exposure to light, and he suspected that the glow produced in cathode ray tubes by X-rays might be associated with phosphorescence. And after a series of research on these and found out the Becquerels rays, which was a breakthrough on the radioactivity of a material. Marie and Pierre Curie’s study of radioactivity is an important factor in science and medicine. After their research on Becquerel’s rays led them to discover both radium and polonium, they coined the term “radioactivity” to define the emission of ionising radiation by some heavy elements.

What is Radioactivity?

Radioactivity is the act of emitting radiation spontaneously. This is done by an atomic nucleus that, for some reason, is unstable; it “wants” to give up some energy to shift to a more stable configuration, or we can say that it is the energy loss process of an unstable nucleus to attain stability.

What is the unit of radioactivity?

Units of radioactivity The number of decays per second, or activity, from a sample of radioactive nuclei, are measured in becquerel (Bq), after Henri Becquerel. One decay per second equals one becquerel.

Some examples of radioactive elements and their stable isotope;

Types of Radioactive decay

Alpha decay occurs when the nucleus ejects an alpha particle (helium nucleus).

Beta-decay: It occurs in two ways:

• beta-minus decay when the nucleus emits an electron and an antineutrino in a process that changes a neutron to a proton.
• Beta-plus decay is when the nucleus emits a positron and a neutrino in a process that changes a proton to a neutron, also known as positron emission.

Gamma decay: In gamma decay, a radioactive nucleus first decays by the emission of an alpha or beta particle. The daughter nucleus that results is usually left in an excited state, and it can decay to a lower energy state by emitting a gamma-ray photon.

Neutron emission: In neutron emission, extremely neutron-rich nuclei, formed due to other types of decay or after many successive neutron captures, occasionally lose energy by way of neutron emission, resulting in a change from one isotope to another of the same element.

Electron capture: In electron capture, the nucleus may capture an orbiting electron, causing a proton to convert into a neutron. A neutrino and a gamma-ray are subsequently emitted.

Cluster decay:A nucleus heavier than an alpha particle is emitted in cluster decay. 

How does Radiation affect humans?

Continuous radiation exposure can cause various problems in the human body; as we know, radiation can completely pass through a human body hence the discovery of X-rays.

Radiation can affect the DNA, which is considered the blueprint of an organism. Radiation can alter its genetic code and increases the chance of it disrupting the crucial DNA molecule. This also increases the possibility that other substances could be introduced that would neutralise free radicals before they do damage. Radiation can also cause mutations in the DNA and cause genetic abnormalities. It can also cause cancer; Cancer is produced if radiation does not kill the cell but creates an error in the DNA blueprint that contributes to eventual loss of control of cell division.

Conclusion

We can conclude by saying that the discovery of radioactivity in certain isotopes has become a breakthrough in nuclear physics. The study of radiation and other factors related to it has helped us in many ways in the field of physics as well as medicine. Radioactivity enhanced biological research and medical progress throughout the 20th century. So we can say it has been a boon to us throughout, but there is also a dark side to it as it can cause many ill effects on us and the environment. It is important to take precautions under these circumstances. We now have a brief idea of what radioactivity is.