A radioactive decay process has a half life of 4 yr. The amount of the reactant remaining after 12 yr is ________.
A radioactive decay process has a half life of 4 yr. The amount of the reactant remaining after 12 yr is 12.5 %.
Radioactive Half-Life Formula. A radioactive half-life refers to the amount of time it takes for half of the original isotope to decay. For example, if the half-life of a 50.0 gram sample is 3 years, then in 3 years only 25 grams would remain. During the next 3 years, 12.5 grams would remain and so on.
Radioactive Decay Rates May Not Be Constant After All. ... Radioactive decay happens when a radioactive substance emits a particle. It's impossible to predict exactly when a given atom of a substance will emit a particular particle, but the decay rate itself over a long period of time is constant.