Tungsten Tungsten Tungsten, or wolfram, is a chemical element with symbol W and atomic number 74. The name "tungsten" comes from the former Swedish name for the tungstate mineral "scheelite", "tung sten" or "heavy stone". Tungsten is a rare metal found naturally on Earth almost exclusively combined with other elements in chemical compounds rather than alone. It was identified as a new element in 1781 and first isolated as a metal in 1783. Its important ores include wolframite and scheelite. The free element is remarkable for its robustness, especially the fact that it has the highest melting point of all the
Francium has a half-life of 56 seconds, although synthetic astatine-210 is much longer-lived with a half-life of 8.1 hours. All isotopes of francium decay into astatine, radium, or radon. Francium-223 also has a shorter half-life than the longest-lived isotope of each synthetic element up to and including element 105, dubnium. Francium is an alkali metal whose chemical properties mostly resemble those of caesium. A heavy element with a single valence electron, it has the highest equivalent weight of any element. Liquid francium—if created—should have a surface tension of 0.05092 N/m at its melting point. Francium's melting point was calculated to be