Chromium Essay

Strontium is a chemical element with symbol Sr and atomic number (protons in nucleus) 38 and atomic weight 88.1 It is a soft, silver-gray metal, and has physical and chemical properties like to Calcium and Barium. It is available as four stable isotopes ubiquitously (Isotopes are differ in forms of an by number of protons in nucleus but possess a variable number of neutrons.) Strontium-88 is the most dominant among other forms, comprising 83% of natural strontium, where in additional three stable isotopes and their relative abundance are strontium-84 (0.6%), strontium-86 (9.9%), and strontium-87 (7.0%). Strontium is available ubiquitous vitally as as celestite (SrSO4) and strontianite (SrCO3), and it comprises about 0.025% of the earth’s crust. There are 16 major radioactive isotopes of strontium, but only strontium-90 has a half-life sufficiently long (29 years). In comparison with half-lives of remaining strontium radionuclides are fewer than 65 days. Strontium-90 decays to yttrium-90 by decaying a beta particle, and yttrium-90 decays by decaying a energetic beta particle with a half-life of 64 hours to zirconium-90. The key health concerns for strontium-90 are associated to the energetic beta particle from yttrium-90.2

Our world, as complex as it is, can be broken down into just 118 different elements. Some of these elements are well known and their names bring vivid images to mind, such as gold, neon, and copper. Other elements, however, are much less recognized. In fact, many people have never even heard of them. Lanthanum is one of these unsung elements. Although, quite often, one may live his entire life without ever hearing of this element, lanthanum is practically everywhere. Far from being a “rare earth” metal, as its name implies, it can be found in many places, from the bones that make up the human form, to the vegetables that make their meals. (1)(4) This poster will tell the fascinating history of lanthanum, some of the physical properties that

Cobalt, the 27th element on the periodic table is the study of this biochemical discussion. Blue in its natural form, it has many uses. To explain further, it uses either come naturally or medicinally. Also, there is important history about cobalt that dates backs to ancient times. Controversy also comes in place when speaking about elements and their interaction with humans and their environment. The current research being done on cobalt is very important as it intervenes with the next topic. The future; how much do we have? Is the right amount of money being put into research? And Is there any research or new ideas on the future uses of cobalt? These questions are ready and want to be answered. Reviewing and processing the words on this page hopefully you will get a further insight to these questions. Ultimately, you will learn more about cobalt’s part in biochemistry.

The risk assessment case study evaluates the chromium-contaminated soils. Twelve years of research went into the study to characterize the health hazards caused by the chromium-contaminated soils. Within New Jersey there were at least three different chromate chemical manufacturing companies operating, one in Kearny, New Jersey, and the other two in Jersey City. The study was conducted through a human health risk assessment, which

Micronucleus test is considered as one of the main cytogenetic parameters, which record partial or whole chromosome breakage during mitosis [17]. Therefore, the efficacy of 5-ALA/PDT to induce DNA damage, and release chromatin during mitosis, was detected by MN test. When MCF-7 and HepG2 cell lines were treated with 5-ALA/PDT at 633nm, the ratio of micronuclei was increased significantly in comparison to non-treated groups. Some research studies demonstrated that not all sensitizers have the ability to induce DNA damage or even cause cytotoxicity when applied with laser irradiation, such studies include the observations of Zenzen and Zankl [23] who demonstrated that h-ALA/PDT did not induce significant chromosome aberrations or micronuclei neither in tumor cell line RPMI 2650 nor fibroblast cell line WS1, however, it caused cytotoxicity to RPMI 2650 tumor cell line. Also, the results of Horinouchi and Arimoto-Kobayashi [27] found that 5-ALA/PDT did not induce photogenotoxicity in keratinocyte NCTC2544 cells as evaluated by MN test, but PpIX disodium salt-induced genotoxicity after exposing the cells to 5-ALA/PDT with UV irradiation of 5J/cm2

Hexavalent Chromium, also known as Chromium 6, is proven to be cancer causing when inhaled and there is strong evidence supporting that it also has a carcinogenic effect when ingested. Hexavalent Chromium is a naturally occurring metal, that can also enter the water supply by industrial contamination.

As seen on the right, Chromium is an element one may assume that it is nothing more than a disheveled piece of shiny silver. However, it is much more than that. Have you ever wondered how shiny car fenders are manufactured or perhaps what makes them so lustrous? To your surprise, or maybe not to your surprise, they are mostly made of the element Chromium! With that said, that is not the only purpose chromium serves.

In this study, scientist found that there are levels of free radicals reactivity of the compounds that are being produced in the cell; some with least reactivity such as H2O2, and some are highly reactive such as OH. The free radicals can affect the cell negatively. One of the element that generates free radicals and causes oxidative stress is cadmium. It increases lipid peroxidation and/or changes intracellular glutathione levels. However, investigators found that some plants such as curcumin is a natural drug that works

Chromium is a transition metal located in Group 6 of the periodic table and is steel grey in its pure form. It is the 21st most abundant element in the earths crust. It has many compounds that are colored, the most important compounds is the chromates of sodium and potassium; the dichromates; and potassium and ammonium chrome alums. Chromium was discovered by Louis-Nicholas Vauquelin in 1797. Vauquelin discovered that he could obtain metallic chromium by heating chromium oxide in a charcoal oven.

Chromium is a transition metal in period number 4 and group number 6 under the symbol Cr and atomic number 24 on the periodic table. It has an atomic weight of 51.9961 rounding to 52, melting point of 2180K and boiling point of 2944K. It was discovered by Louis-Nicholas Vauquelin in 1797.

The history of the element is very interesting, because it came from a Greek word. But it was discovered in France, by Louis Nicolas Vauquelin. Chromium is able to stand into room temperature, most elements can’t do that. This is possibly the only element that can do that. Chromium is a special element by its history. And by this history chromium is

Precious metals do not have their own group on the periodic table. They are arranged together on the table. These elements do have the same chemical properties, however they do not have their own classification. All of these metals do not rust, they are resistant to oxidation and corrosion and they only break down when they are in high temperatures. Gold (Au), silver (Ag), platinum (Pt), ruthenium (Ru), rhodium (Rh), palladium (Pd), iridium (Ir), and osmium (Os) all have similar properties and are considered to be precious metals.1

I learned about my element that the gaseous form does not occur in nature at all. Chlorine is found in nature only with sodium and other elements and never found

Chromium (Cr) is a metallic element present in soils, waters, rocks, fauna and flora, and volcanic and dust gases. Although chromium is the 22nd most abundant element in the Earth’s crust with an average concentration of 100 ppm, the free metal is never found in nature. (Emsley, John (2001). "Chromium". Nature's Building Blocks: An A-Z Guide to the Elements. Oxford, England, UK: Oxford University Press. pp. 495–498.ISBN 0-19-850340-7.) (Encyclopædia Britannica Online, s. v. "chromium (Cr)", accessed July 15, 2015,http://www.britannica.com/science/chromium.) The commercial source of chromium is chromite, a mineral oxide of chromium and iron (FeCr2O4). The principal producing areas of chromite are South Africa, Russia, Albania, the Philippines, Zimbabwe, Turkey, Brazil, India, and Finland. (Encyclopædia Britannica Online, s. v. "chromite", accessed July 15, 2015,http://www.britannica.com/science/chromite.)

•it occurs naturally in its pure,free form as an alloy with gold and other metals, and in minerals such as argentite and chlorargyrite