GEOLOGY

Detailed explanation-1: -Half-life (symbol t½) is the time required for a quantity (of substance) to reduce to half of its initial value. The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay or how long stable atoms survive.

Detailed explanation-2: -It is impossible to predict when an individual radioactive atom will decay. The half-life of a certain type of atom does not describe the exact amount of time that every single atom experiences before decaying.

Detailed explanation-3: -Half-life is the length of time it takes for half of the radioactive atoms of a specific radionuclide to decay. A good rule of thumb is that, after seven half-lives, you will have less than one percent of the original amount of radiation.

Detailed explanation-4: -Half-Life is normally defined as the time needed by a radioactive substance (or one half the atoms) to disintegrate or transform into a different substance. The principle was first discovered in 1907 by Ernest Rutherford. It is usually represented by the symbol Ug or t1/2.