who is christopher knight dating 2016 - Two types of radiometric dating

The decay rate and therefore the half-life are fixed characteristics of a nuclide. Thats the first axiom of radiometric dating techniques: the half-life of a given nuclide is a constant.

The rules are the same in all cases; the assumptions are different for each method.

To explain those rules, I'll need to talk about some basic atomic physics. Hydrogen-1's nucleus consists of only a single proton.

Some nuclides have very long half-lives, measured in billions or even trillions of years.

Others have extremely short half-lives, measured in tenths or hundredths of a second.

Uranium-238 contains 92 protons and 146 neutrons, while uranium-235 contains 92 protons and 143 neutrons.