Radiometric dating rock samples
In other words there was originally 4 parts per million Parentium-123 and 0 parts per million Daughterium-123.Since there is now only 1/4 of the original amount of Parentium-123, we know that two half-lives of Parentium-123 have elapsed.Imagine we have an undiscovered element, Parentium, that has a radioactive isotope, Parentium-123, which decays to stable Daughterium-123.This is the only way Parentium-123 decays, and there is no other source of Daughterium-123.In calculus terms, we write: d N(t)/dt = -K * N(t) or d N(t)/N(t) = -K dt The minus sign means that each decay decreases the total number of atoms.Integrating both sides, we get: ln N(t) = -Kt C C is the constant of integration that we can often ignore, but not here.A minimum age is the youngest the object can possibly be.
Let t stand for time and N(t) stand for the number of atoms at time t .
Rubidium-strontium dating is more robust, and uranium-lead dating can survive fairly significant metamorphism without resetting.
If a system gains or loses isotopes in a predictable way, it may be possible to estimate the loss and correct the age.
We could be sure that a mineral containing parentium originally had no daughterium.
If the mineral contained 1 part per million Parentium-123 and 3 parts per million Daughterium-123, we could be sure all the Daughterium-123 was originally Parentium-123.Carbon-14 dating is often used for historical objects and young prehistoric objects, but it's based on the fact that all living things start out with a known amount of carbon-14. If the arrowhead is stuck in a bone, you can date the bone.