… Radioactive chemical elements and radioactive isotopes (including the fissile or fertile chemical elements and isotopes) and their compounds; mixtures and …
Explanatory notes
… isotopic composition but one which varies according to the method of obtaining the element, it is impossible in these … effects make it possible to detect these radiations and to measure their intensity by using, for example, Geiger‑Müller … curium, berkelium, californium, einsteinium, fermium, mendelevium, nobelium and lawrencium. These are elements …