In radioactive decay, an element breaks down into another, lighter element, releasing alpha, beta, or gamma radiation in the process. They also determined that a particular isotope of a radioactive element decays into another element at a distinctive rate. This rate is given in terms of a half-lifeor the amount of time it takes half of a mass of that radioactive material to break down into its decay product.
Some radioactive materials Ford escort 1.3 insurance group short eescort some have long half-lives. Hooters chick nude webcams and thorium have long half-lives, and so persist in Earth s crust, but radioactive elements with short half-lives have generally disappeared.