Terms Associated with Radioactivity

Half-Life

The half-life of a radioactive element is defined as the time taken for half of the number of atoms of the element to disintegrate. It is a constant quantity for an element. Thus if the half-life of a radioactive substances in one hour, then it means that during one hour half the substance would decay. And during the next one hour half of the remaining substance (i.e., three-fourth of the initial substance) would decay. The half-lives of different elements range from 10-7 seconds to 1010 years.

Transmutation

The changing of one element to another is called transmutation. Beside natural transmutation going on in the form of natural radioactivity, artificial transmutation can also be achieve by bombarding elements with highly energetic projectiles, electrons and protons, obtained from giant accelerators. Artificial transmutation has been used to obtain elements with atomic number greater than 92 (called transuranic elements). By artificial transmutation all the elements can now be made radioactive.

Radioactive isotopes

Radioactive isotope (or radioisotopes) is produced by irradiating substances with neutrons in a nuclear reactor or by bombarding with high energy particles from accelerators. Radioisotopes are being increasingly used in scientific research, medicine, agriculture and industry.

Carbon Dating

This is the technique of estimating the age of the remains of a once-living organism, such as a plant or an animal, by measuring the radioactivity of its carbon-14 content.