What different elements are used in radiometric dating
When t = 0, ln N(0) = C Taking exponentials of both sides, we get N(t) = N(0)exp(-Kt) If t = one half life, then N(t)/N(0) = 1/2 = exp(-Kt), and: ln(1/2) = -ln2 = -Kt, so t = ln2 / K So what we do in practice is determine the decay constant and calculate half life from it.If the decay constant is very small, even tiny amounts of contamination by other radioactive materials can be very significant.Potassium-argon dating is very susceptible to resetting because the argon decay products are merely held in place mechanically by surrounding atoms.
Let t stand for time and N(t) stand for the number of atoms at time t .
So accurate determinations require very pure samples, very accurate and selective detectors, or both.
The true age of a sample is self-explanatory, but unless the material dates from historic times, the true age is rarely known.
Sedimentary rocks are generally hard to date because common cements like silica don't have datable radioisotopes, and minerals like glauconite that are common in sedimentary rocks are very prone to resetting.
If only there were long-lived isotopes of silicon, calcium, and magnesium!