What is the definition of half-life in radioactive decay?

The definition of half-life in radioactive decay is the time required for half of a radioactive substance to decay. This concept is fundamental in nuclear chemistry and helps us understand how materials change over time due to radioactive processes.

Radioactive decay occurs at a predictable rate for each isotope, and half-life quantifies this rate. For instance, if a sample has a half-life of 5 years, after 5 years, half of the original amount of the radioactive substance will have decayed into other elements or isotopes. After another 5 years (a total of 10 years), half of what remained will have decayed, leaving a quarter of the original amount. This consistent halving over successive periods is what characterizes and defines half-life.

Understanding half-life is crucial when discussing the safety and use of radioactive materials, estimating ages in radiometric dating, or calculating the disposal of nuclear waste, among other applications.