Uranium was discovered by Martin Heinrich Klaproth,
a German chemist, in the mineral pitchblende in 1789. Klaproth and the rest of the scientific community believed that the
substance he extracted was pure uranium, it was actually uranium dioxide. Eugéne-Melchoir Péligot, a French chemist, isolated
pure uranium by heating uranium dioxide with potassium in a platinum crucible. Radioactivity was first discovered in 1896
when Antoine Henri Becquerel, a French physicist, detected it from a sample of uranium.