Chromium is a chemical element with the symbol Cr and atomic number 24. It is the first element in group 6, it is a steely-grey, lustrous and brittle transition metal. Chromium is the main additive in stainless steel. Chromium is highly valued as a metal, able to be polished while resisting tarnishing. Polished chromium reflects 70% of the visible spectrum, with 90% of infrared light being reflected; the name of the element is derived from the Greek word χρῶμα, chrōma, meaning color, because many chromium compounds are intensely colored. Ferrochromium alloy is commercially produced from chromite by silicothermic or aluminothermic reactions and chromium metal by roasting and leaching processes followed by reduction with carbon and aluminium. Chromium metal is of high value for hardness. A major development in steel production was the discovery that steel could be made resistant to corrosion and discoloration by adding metallic chromium to form stainless steel. Stainless steel and chrome plating together comprise 85% of the commercial use.
In the United States, trivalent chromium ion is considered an essential nutrient in humans for insulin and lipid metabolism. However, in 2014, the European Food Safety Authority, acting for the European Union, concluded that there was not sufficient evidence for chromium to be recognized as essential. While chromium metal and Cr ions are not considered toxic, hexavalent chromium is both toxic and carcinogenic. Abandoned chromium production sites require environmental cleanup. Chromium is the fourth transition metal found on the periodic table, has an electron configuration of 3d5 4s1, it is the first element in the periodic table whose ground-state electron configuration violates the Aufbau principle. This occurs again in the periodic table with other elements and their electron configurations, such as copper and molybdenum; this occurs. In the previous elements, the energetic cost of promoting an electron to the next higher energy level is too great to compensate for that released by lessening inter-electronic repulsion.
However, in the 3d transition metals, the energy gap between the 3d and the next-higher 4s subshell is small, because the 3d subshell is more compact than the 4s subshell, inter-electron repulsion is smaller between 4s electrons than between 3d electrons. This lowers the energetic cost of promotion and increases the energy released by it, so that the promotion becomes energetically feasible and one or two electrons are always promoted to the 4s subshell. Chromium is the first element in the 3d series where the 3d electrons start to sink into the inert core. Chromium is a strong oxidising agent in contrast to the tungsten oxides. Chromium is hard, is the third hardest element behind carbon and boron, its Mohs hardness is 8.5, which means that it can scratch samples of quartz and topaz, but can be scratched by corundum. Chromium is resistant to tarnishing, which makes it useful as a metal that preserves its outermost layer from corroding, unlike other metals such as copper and aluminium. Chromium has a melting point of 1907 °C, low compared to the majority of transition metals.
However, it still has the second highest melting point out of all the Period 4 elements, being topped by vanadium by 3 °C at 1910 °C. The boiling point of 2671 °C, however, is comparatively lower, having the third lowest boiling point out of the Period 4 transition metals alone behind manganese and zinc; the electrical resistivity of chromium at 20 °C is 125 nanoohm-meters. Chromium has a high specular reflection in comparison to other transition metals. In infrared, at 425 μm, chromium has a maximum reflectance of about 72%, reducing to a minimum of 62% at 750 μm before rising again to 90% of 4000 μm; when chromium is used in stainless steel alloys and polished, the specular reflection decreases with the inclusion of additional metals, yet is still high in comparison with other alloys. Between 40% and 60% of the visible spectrum is reflected from polished stainless steel; the explanation on why chromium displays such a high turnout of reflected photon waves in general the 90% in infrared, can be attributed to chromium's magnetic properties.
Chromium has unique magnetic properties in the sense that chromium is the only elemental solid which shows antiferromagnetic ordering at room temperature. Above 38 °C, its magnetic ordering changes to paramagnetic; the antiferromagnetic properties, which cause the chromium atoms to temporarily ionize and bond with themselves, are present because the body-centric cubic's magnetic properties are disproportionate to the lattice periodicity. This is due to the fact that the magnetic moments at the cube's corners and the cube centers are not equal, but are still antiparallel. From here, the frequency-dependent relative permittivity of chromium, deriving from Maxwell's equations in conjunction with chromium's antiferromagnetivity, leaves chromium with a high infrared and visible light reflectance. Chromium metal left standing in air is passivated, i.e. forms a thin, surface layer of oxide. This layer has a spinel structure, only a few atomic layers thick, it is dense and inhibits the diffusio
"How I Could Just Kill a Man" is the debut single by hip hop group Cypress Hill from their eponymous debut album, Cypress Hill, was their first major hit in 1991. It was released as a double A-side to "The Phuncky Feel One" and the music video featured cameos by A Tribe Called Quest's Q-Tip and Ice Cube, with whom the group would feud; the song was in the movie Juice. It was re-released in 1999 with a new video, it is featured as the first track on their greatest hits compilation Greatest Hits from the Bong. The song was featured on the 2004 video game Grand Theft Auto: San Andreas, appearing on the West Coast hip hop station Radio Los Santos, it was voted number 79 in About.com's Top 100 Rap Songs. Towards the end of the song someone is heard saying, "All I wanted was a Pepsi"; this quote is taken from the well-known Suicidal Tendencies song, "Institutionalized". In 2001, Cypress Hill included a sequel to the song on their album Stoned Raiders entitled "Here Is Something You Can't Understand", using the same chorus but with new verses from B-Real, Sen Dog and guest Kurupt.
NOTE: "The Killer Mix" is the uncensored album version of the song. The song was covered by rap metal band Rage Against the Machine on their cover album, where the song was released as a single. Rage Against the Machine performed the song on their DVD, Live at the Grand Olympic Auditorium, accompanied by Cypress Hill. "How I Could Just Kill a Man" – 4:04 Singer Charlotte Sometimes named the first single from her debut album Waves and the Both of Us "How I Can Just Kill a Man" in honor of Cypress Hill, though the songs have no other similarities. The song became a staple on both VH1 and MTV during the summer of 2008 and closed her set on the Vans Warped Tour, it is covered by B-star on their album What We Do A cover version was released in 1994 by German Hamburger Schule band Cpt. Kirk &. on the album "Round About Wyatt", but with the song's title changed to "How He Could Just Kill A Man". Lyrics of this song at MetroLyrics
Portsea is a township, south-east of Melbourne, Australia. It is located 108 kilometres south of the Melbourne CBD, on the opposite side of Port Phillip Bay; the townsite is located on the bay itself, but the locality boundaries stretch as far west as Point Nepean and incorporate a section of Bass Strait coastline. Portsea is the westernmost town on the Mornington Peninsula, lies adjacent to the town of Sorrento, it has one of the highest average incomes in Australia. Portsea is named after Portsea Island, an island incorporated by Portsmouth, England. Portsmouth is. Portsea Post Office opened on 10 February 1877 and closed in 1987. OCS Portsea, an army establishment, was located just outside the town; the historic reserve became famous when Prime Minister of Australia Harold Holt disappeared while swimming inside the facility at Cheviot Beach on 17 December 1967 and was presumed dead two days although a formal inquest into his death did not take place until 2005. Portsea was considered by many to be the hub of Melbourne's recreational scuba diving activities.
At one time there were as many as four dive shops in the main street of Portsea. Dive charter boats still travel from Portsea Pier to sites both inside Port Phillip and outside Port Phillip Heads known as "The Rip"; the Portsea Pier is the home to the spectacular weedy sea dragon, as well as many other fish species, including numerous pufferfish. Boating traffic is frequent, divers should be careful to avoid main boating routes. After dredging was done to deepen the entrance to the bay for shipping there was increased surge at Portsea Pier and within a year Portsea Beach was gone. Portsea Back Beach is a big attraction in Portsea, due to its great surfing conditions and long stretch of sand. Portsea Surf Life Saving Club patrols the popular surf beach, as patrols are always needed during the summer period given the large waves and strong tides that are present. Corsair Rock, just at the entrance to Port Philip, is a well-known surf spot to locals and professional surfers. However, it is not advised to surf there unless you are an experienced surfer and, for safety, are accompanied by somebody in a boat nearby.
It is considered a dangerous location. The rip can run out as fast as 8-10 knots. Golfers play at the revered Portsea Golf Club on Relph Avenue; the annual Portsea Polo event is held at Jarman Oval, near the former quarantine station on Point Nepean. According to the 2016 Australian Bureau of Statistics Census, Portsea had 510 residents. Prominent residents include trucking magnate Lindsay Fox, Kate Baillieu and Rupert Murdoch's grandson businessman David Calvert Jones, other well known residents are Eddie McGuire and Ron Walker; the formally recognised Traditional Owners for the area in which Portsea is located are the Bunurong People. The Bunurong People are represented by the Bunurong Land Council Aboriginal Corporation; the Australian Crawl song "Hoochie Gucci Fiorucci Mama" was written about Portsea. Portsea Hole, a nearby dive location Media related to Portsea, Victoria at Wikimedia Commons