NOUN
- a short-lived radioactive metallic element formed from uranium and disintegrating into actinium and then into lead
How To Use protoactinium In A Sentence
- Thus were found the mesothorium now used by physicians and manufactured industrially, radio-thorium, ionium, protoactinium, radio-lead, and other substances. Pierre Curie
- Thus were found the mesothorium now used by physicians and manufactured industrially, radio-thorium, ionium, protoactinium, radio-lead, and other substances. Pierre Curie
- That's radioactive, but it takes two million years before it becomes protoactinium, which changes to uranium in twenty-seven days, which changes to thorium after a hundred and sixty thousand years, which changes to radium, then to actinium, then to -- Asimov's Science Fiction
