Uranium-234 has a half-life of 246,000 years. How did we measure that if the technology to do that hasn’t been around that long?

Question

Uranium-234 has a half-life of 246,000 years. How did we measure that if the technology to do that hasn’t been around that long?

In: Chemistry

Answer 1

You don’t need to wait 246,000 years to know.

You just measure the decay of a know quantity over a known time period and extrapolate that curve out to when you hit 50% decay.

For very long half-lives you need a bigger sample and/or a longer test time and/or a more sensitive detector but unless the half-life is so long that you “never” get a decay, you can gather the data and plot the curve with relative ease.