RADIOTHORIUMS

RADIOTHORIUMS is a 13 letter Scrabble word worth 19 points.

an isotope of thorium (thorium-228) which occurs in small amounts in natural thorium and is formed by the beta decay of actinium-228, and which itself decays by alpha emission with a half-life of 1.9 years; (also) a mixture of radioactive isotopes of thorium, actinium, and radium, present as decay products in natural thorium.

Letter start with R