Justin Taylor
Mrs.Lewis
Tungsten
Title of Your Report
Tungsten, also known as wolfram, is a chemical element with symbol W and atomic number 74. The word tungsten comes from the Swedish language tung sten, which directly translates to heavy stone. Its name in Swedish is volfram, however, in order to distinguish it from scheelite, which in Swedish is alternatively named tungsten.
A hard, rare metal under standard conditions when uncombined, tungsten is found naturally on Earth only in chemical compounds. 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
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and a much lower superconducting transition temperature TC relative to the β phase: ca. 0.015 K vs. 1–4 K; mixing the two phases allows obtaining intermediate TC values. The TC value can also be raised by alloying tungsten with another metal . Such tungsten alloys are sometimes used in low-temperature superconducting circuits.
Isotopes
Naturally occurring tungsten consists of five isotopes whose half-lives are so long that they can be considered stable. Theoretically, all five can decay into isotopes of element 72 by alpha emission, but only 180W has been observed to do so with a half-life of ×1018 years; on average, this yields about two alpha decays of 180W in one gram of natural tungsten per year. The other naturally occurring isotopes have not been observed to decay, constraining their half-lives to be:
Another 30 artificial radioisotopes of tungsten have been characterized, the most stable of which are 181W with a half-life of 121.2 days, 185W with a half-life of 75.1 days, 188W with a half-life of 69.4 days, 178W with a half-life of 21.6 days, and 187W with a half-life of 23.72 h. Tungsten typically combines with oxygen to form the yellow tungstic oxide, WO3, which dissolves in aqueous alkaline solutions to form tungstate ions,
The following picture shows the CVD growth for WS2. The yield is not very High like MoS2, it is only on the center sample and triangle size up to 80um. To improve the growth, we need to reduce the sulfur flux, and increase the Tungsten trioxide (WO3) flux by changing temperature or quantities. Also, we should increase the growth time.
Technetium -99m is produced by bombarding molybdenum 98Mo with neutrons. The resultant 99Mo decays with a half-life of 66 hours to the metastable state of Tc. This process permits the production of 99mTc for medical purposes. Since 99Mo is a fission product of 235U fission, it can be separated from the other fission products and used to generate 99mTc. For medical purposes, the 99mTc is used in the form of
A half life lab was conducted by rolling pennies in a cup, and then setting aside those which were heads down. This process represents a half-life of the atom, or the time required for half of a substance sample to decay. The purpose of performing this lab was to simulate the transformation of a radioisotope over time, and to graph the data in a way that relates it to radioactive decay and half-lives. The presumed result of this experiment was that a little less than half the pennies would be face down due to some inconsistencies when shaking and pouring the pennies out of the cup.
These crystals were first discovered back in 2004 by Subramanian Ramaswamy, who was studying at the University of Iowa in Iowa City. To learn
Zinc, in commerce also spelter, is a chemical element with symbol Zn and atomic number 30. It is the first element of group 12 of the periodic table. In some respects zinc is chemically similar to magnesium: its ion is of similar size and its only common oxidation state is +2. Zinc is the 24th most abundant element in Earth's crust and has five stable isotopes. The most common zinc ore is sphalerite (zinc blende), a zinc sulfide mineral. The largest mineable amounts are found in Australia, Asia, and the United States. Zinc production includes froth flotation of the ore, roasting, and final extraction using electricity (electrowinning).
Tungsten, formerly Wolfram or Wolframite, is not naturally found in nature, and can only be created by taking either protons or neutrons from naturally occurring substances. In the sixteenth century, German smelters discovered it as an accompanying mineral to tin ores. When trying to smelt these ores, they sometimes found foam like deposits would form, consuming the tin ores they found valuable. Due to this phenomenon, it was said that it “Tears away the tin and devours it like a wolf devours sheep.” and labeled somewhat of a nuisance material. The name wolfram was also due to the substances black color and its hairy appearance. A century and a half later it would be given the name Tungsten after another tungsten ore called
Tungsten is a silvery white metal, has the highest melting point of any metal and is durable.
Molybdenum and tungsten have similar ionic radii and chemical properties. Tungsten is the heaviest atom and the only third-row transition element that exhibits biological activity in enzymes. Molybdenum is the only second-row transition metal that exhibits biological activity when it is present in a cofactor of a metalloenzyme. The natural source of molybdenum is molybdate, molybdate has 4 oxygens bound to the molybdenum in a tetrahedral coordination and is transported into the cell by ModA, where it is incorporated into the molybdoenzymes, or in various different cofactor. Tungsten is also taken up by cells in a similar manner as molybdenum but is bound by a different protein WtpA. Tungsten occurs naturally as tungstate, just like molybdate it has 4 oxygens bound a tetrahedral. Humans need molybdenum for molybdoenzymes which are essential for our growth, in thermophiles the molybdenum is usually substituted for tungsten. (Mukund & Adams, 1991) Not all life form use molybdenum and not all use tungsten, but all use either molybdenum or tungsten, to current date there has not been a cell found that doesn’t use one or the other. The molybdoenzymes carry out a variety of different reactions in both prokaryotes and eukaryotes. One of the most well-known one being nitrogenase as well as nitrate reductase. These work together to play a major role in our ecosystem. There are a number of other
Nickel, an element on the periodic table has many different isotopes, but the two that stand out the most are Nickel-58 and Nickel-63.
Tungsten is widely used in military to fabricate armor piercing ammunition and used to infiltrate substantial solidified heavily clad targets, for example, defensively covered vehicles, solid shelters, tanks and different guards. Contingent upon the gauge of the guns. It is ammo comprises of a penetrator developed of tungsten amalgam or tungsten carbide, or exhausted uranium, encased inside of a milder coat, for example, copper or aluminum. The item ammo can extend from rifle-and gun gauge gathers the distance together to tank rounds.
There are only 2 known isotopes of Cobalt. Cobalt-59 is the only naturally occurring isotope of Cobalt. This means that the only cobalt that will ever be found in nature is cobalt with 32 neutrons. Cobalt-60 is a man-made isotope of cobalt. This radioactive isotope was discovered by Glenn Seaborg in the late 1930’s at the University of California. Cobalt-60 is an important source of gamma radiation and is used in some medical fields to treat cancer.
When it comes to the Mohs Scale of Hardness, the very hardest material known to man is diamond, which most people know. What they might not know is that tungsten comes in second on that list. Where diamonds have a hardness of 10, tungsten carbide is a
This element that is called Sodium has a very soft sort of silvery outer layer. Once sodium is cut the surface of the sodium will then air out into a dull kind of oxidized coating. Sodium is a very reactive chemical element that is found in the planet's crust. 2.6% of the earth's crust is sodium, and the reason that we can't find any sort or sodium on the ground is because sodium is reactive to any sort of the earth's moisture can and will have a chemical reaction and the piece of sodium will explode. Did you know that Sodium is one of the sixth most abundant materials in the world. In order to find sodium we have to dig into the earth to get a hold of this chemical product. The chemical
Scandium is the element that I have chosen to study and discover its history, it was discovered by Swedish chemist, Lars Fredrik Nilson in 1876, the name ‘Scandium’ stems from the latin word ‘Scandia’ meaning Scandinavia which was his homeland, at that time it was only found in Scandinavia hence the meaning behind the name. The first discovery of it was in a large rock that contained minerals euxenite and gadolinite from the Earth’s crust, inside those elements was Scandium.
XPS measurement was used to investigate the chemical state of the tungsten and boron species in 40 wt% WO3/UiO-66 and 15 wt% B2O3-40 wt% WO3/UiO-66 samples. Fig. 7(A) shows the W 4f XPS spectrum and the curve-fitting result of 40 wt% WO3/UiO-66 sample. Tungsten species appear in two different states in 40 wt% WO3/UiO-66 material. The peaks with the binding energies at 35.3 and 37.5 eV are associated with W5+ species, whereas the peaks at 34.6 and 36.8 eV can be assigned to W6+ species. The corresponding results for 15 wt% B2O3-40 wt% WO3/UiO-66 sample are shown in Fig. 7(B). The XPS spectrum of 15 wt% B2O3-40 wt% WO3/UiO-66 material appears to be same as that of 40 wt% WO3/UiO-66 material and shows identical positions for the W4f peaks, except for the minor charging effect. Both W5+ and W6+ species are detected; however, the molar ratio of W6+/W5+ calculated according to the relative peak intensity of W4f increases from 2.1 to 2.2 (Table 2) after the introduction of B2O3 species as an active additive promoter, suggesting that the content of W6+ species on the surface of B2O3-WO3/UiO-66 sample increases and forms some aggregated tungsten