Difference between Radiothorium and Thorium-228

What is the difference between Radiothorium and Thorium-228?

Radiothorium as a noun is the radioactive isotope thorium-228 while Thorium-228 as a noun is a radioactive isotope of thorium, , having a half-life of 1.4 x 1010 years; it occurs naturally, and is a source of nuclear energy

We hope you now know whether to use Radiothorium or Thorium-228 in your sentence.