Uranium tile Uranium tile Uranium tiles have been used in the ceramics industry for many centuries, as uranium oxide makes an excellent ceramic glaze, and is reasonably abundant on the earth's crust. Not long after Henri Becquerel discovered radioactivity in uranium salts, Madame Curie discovered both polonium and radium as two new radioactive elements also present with uranium. The relatively high specific activity and moderate half-life of 1,600 years of Ra-226, the main radioisotope of radium found in uranium ore, made for a material which when mixed with a phosphor allowed for a glow-in-the-dark substance. Thus, in addition to its medical usage,
Transactinide element atomic number greater than uranium (92). The transactinide elements all have electrons in the 6d subshell in their ground state. Except for rutherfordium and dubnium, even the longest-lasting isotopes of transactinide elements have extremely short half-lives, measured in seconds, or smaller units. The element naming controversy involved the first five or six transactinide elements. These elements thus used systematic names for many years after their discovery had been confirmed. (Usually the systematic names are replaced with permanent names proposed by the discoverers relatively shortly after a discovery has been confirmed.) Transactinides are radioactive and have only been obtained synthetically in