"There are four stable isotopes of tungsten, the commonest on earth being W-134 which accounts for 30.6% of the tungsten found terrestrially. Isotopes W-186, W-182 and W-183 account for 28.4%, 26.5% and 14.3% respectively 2. A fifth isotope, W-180, is technically unstable but has a half-life ~1.5 × 1018 years. It accounts for a mere 0.1% terrestrial tungsten 2."
"So, they named their element wolfram, but the name tungsten had already become well-known in the English-speaking chemistry world. In the past, IUPAC had recognised both names, but in 2005 it decided that tungsten would be the official international name for the element 1."
"At room temperature, tungsten is a solid steel-gray-to-white transition metal that is hard and brittle. It only becomes ductile (able to be drawn into wires) at a temperature of 700 °C. Thermomechanical processing and alloying with another metal rhenium can improve the ductility of tungsten at lower temperatures 10."
"In 1758, the Swedish chemist Axel Fredrik Cronstedt found an especially weighty mineral, which he called “tung sten”, literally ‘heavy stone’, and he thought contained a novel element 4. Another Swedish chemist, Carl Wilhelm Scheele (1742-1786), isolated tungsten trioxide (WO3) from an acid derivative of the scheelite (the modern term for the tungsten mineral) in 1781 7,8. It was only two years later in 1783 that two Spanish brothers, Juan and Fausto Elhuyar, fully purified the element from wolframite, an ore, by reducing tungsten trioxide with charcoal, and they are recognised as the true ‘discoverers’ of the element 4,8."
Expected headings
"Basic chemistry"
"Medical importance"
"Tungsten (chemical symbol, W) is a hard refractory metallic element with remarkable resilience which forms the basis for its industrial uses. It is the metal of choice in the filaments and targets of x-ray tubes. There is no evidence that tungsten is required by the human body, although some micro-organisms do use it."
"There are four stable isotopes of tungsten, the commonest on earth being W-134 which accounts for 30.6% of the tungsten found terrestrially. Isotopes W-186, W-182 and W-183 account for 28.4%, 26.5% and 14.3% respectively 2. A fifth isotope, W-180, is technically unstable but has a half-life ~1.5 × 1018 years. It accounts for a mere 0.1% terrestrial tungsten 2."
"There is contentious evidence that chronic occupational exposure to tungsten compounds (e.g. tungsten carbide) may have deleterious biological effects in people. Some metal workers have presented with symptoms following long-term cutaneous and/or respiratory exposure to mineral dusts. However, it is very difficult, if not impossible, to separate this out from coexisting dusts of other metals, e.g. cobalt, which are more likely the main culprit in these scenarios 3,4."
"There is contentious evidence that chronic occupational exposure to tungsten compounds (e.g. tungsten carbide) may have deleterious biological effects in people. Some metal workers have presented with symptoms following long-term cutaneous and/or respiratory exposure to mineral dusts. However, it is very difficult, if not impossible, to separate this out from coexisting dusts of other metals, e.g. cobalt, which are more likely the main culprit in these scenarios 3,4."
"In 1758, the Swedish chemist Axel Fredrik Cronstedt found an especially weighty mineral, which he called “tung sten”, literally ‘heavy stone’, and he thought contained a novel element 4. Another Swedish chemist, Carl Wilhelm Scheele (1742-1786), isolated tungsten trioxide (WO3) from an acid derivative of the scheelite (the modern term for the tungsten mineral) in 1781 7,8. It was only two years later in 1783 that two Spanish brothers, Juan and Fausto Elhuyar, fully purified the element from wolframite, an ore, by reducing tungsten trioxide with charcoal, and they are recognised as the true ‘discoverers’ of the element 4,8."
"In 1758, the Swedish chemist Axel Fredrik Cronstedt found an especially weighty mineral, which he called “tung sten”, literally ‘heavy stone’, and he thought contained a novel element 4. Another Swedish chemist, Carl Wilhelm Scheele (1742-1786), isolated tungsten trioxide (WO3) from an acid derivative of the scheelite (the modern term for the tungsten mineral) in 1781 7,8. It was only two years later in 1783 that two Spanish brothers, Juan and Fausto Elhuyar, fully purified the element from wolframite, an ore, by reducing tungsten trioxide with charcoal, and they are recognised as the true ‘discoverers’ of the element 4,8."