On this day February 4, 1936
Radium E becomes the first radioactive element to be made synthetically.
Radium (Latin radius, ray) was discovered by Marie Skłodowska-Curie and her husband Pierre in 1898 in pitchblende from North Bohemia, in the Czech Republic (area around Jáchymov).
While studying pitchblende the Curies removed uranium from it and found that the remaining material was still radioactive.
They then separated out a radioactive mixture consisting mostly of barium which gave a brilliant green flame color and crimson carmine spectral lines which had never been documented before. The Curies announced their discovery to the French Academy of Sciences on 26 December 1898.
In 1902, radium was isolated as a pure metal by Curie and André-Louis Debierne through the electrolysis of a pure radium chloride solution by using a mercury cathode and distilling in an atmosphere of hydrogen gas.
On February 4, 1936 radium E became the first radioactive element to be made synthetically.
Radium is over one million times more radioactive than the same mass of uranium. Its decay occurs in at least seven stages; the successive main products have been studied and were called radium emanation or exradio (now identified as radon), radium A (polonium), radium B (lead), radium C (bismuth), etc. Radon is a heavy gas and the later products are solids. These products are themselves radioactive elements, each with an atomic weight a little lower than its predecessor.