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Dividing Line Between Metals And Nonmetals
The dividing line between metals and nonmetals can be found, in varying configurations, on some representations of the periodic table of the elements (see mini-example, right). Elements to the lower left of the line generally display increasing metallic behaviour; elements to the upper right display increasing nonmetallic behaviour. When presented as a regular stair-step, elements with the highest critical temperature for their groups (Li, Be, Al, Ge, Sb, Po) lie just below the line. Names This line has been called the ''amphoteric line,'' Levy 2001, p. 158 the ''metal-nonmetal line,'' the ''metalloid line,'' the ''semimetal line,'' or the ''staircase.'' While it has also been called the ''Zintl border'' or the ''Zintl line'' these terms instead refer to a vertical line sometimes drawn between groups 13 and 14. This particular line was named by Laves in 1941. It differentiates group 13 elements from those in and to the right of group 14. The former generally combine with elect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metal
A metal (from Greek μέταλλον ''métallon'', "mine, quarry, metal") is a material that, when freshly prepared, polished, or fractured, shows a lustrous appearance, and conducts electricity and heat relatively well. Metals are typically ductile (can be drawn into wires) and malleable (they can be hammered into thin sheets). These properties are the result of the ''metallic bond'' between the atoms or molecules of the metal. A metal may be a chemical element such as iron; an alloy such as stainless steel; or a molecular compound such as polymeric sulfur nitride. In physics, a metal is generally regarded as any substance capable of conducting electricity at a temperature of absolute zero. Many elements and compounds that are not normally classified as metals become metallic under high pressures. For example, the nonmetal iodine gradually becomes a metal at a pressure of between 40 and 170 thousand times atmospheric pressure. Equally, some materials regarded as metals ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boron Group
The boron group are the chemical elements in group 13 of the periodic table, comprising boron (B), aluminium (Al), gallium (Ga), indium (In), thallium (Tl), and nihonium (Nh). The elements in the boron group are characterized by having three valence electrons. These elements have also been referred to as the triels. Boron is commonly classified as a (metalloid) while the rest, with the possible exception of nihonium, are considered post-transition metals. Boron occurs sparsely, probably because bombardment by the subatomic particles produced from natural radioactivity disrupts its nuclei. Aluminium occurs widely on earth, and indeed is the third most abundant element in the Earth's crust (8.3%). Gallium is found in the earth with an abundance of 13 ppm. Indium is the 61st most abundant element in the earth's crust, and thallium is found in moderate amounts throughout the planet. Nihonium is not known to occur in nature and therefore is termed a synthetic element. Several group ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alexander Smith (chemist)
Prof Alexander Smith FRSE LLD (11 September 1865 – 8 September 1922) was a Scottish chemist, who spent his working life teaching in the universities of America. Biography He was born at 4 Nelson Street in Edinburgh's New Town, the son of Isabella (née Carter) and Alexander W. Smith, a music teacher. His paternal grandfather was the sculptor Alexander Smith. The family moved to 4 West Castle Road in the Merchiston district while he was young. He was educated at Edinburgh Collegiate School. He studied sciences (later specialising in chemistry) at the University of Edinburgh. He was taught mathematics by George Chrystal, physics by Peter Guthrie Tait and chemistry by Alexander Crum Brown. He graduated BSc in 1886. During his university years he showed a keen interest in astronomy and published four papers on the subject. He went to Germany in 1886 for further postgraduate studies and gained his doctorate at the University of Munich under Prof Rainer Ludwig Claisen in Baeyer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gustavus Detlef Hinrichs
Gustavus Detlef Hinrichs (2 December 1836 – 14 February 1923) was a chemist and natural philosopher most widely known for his findings on periodic laws within the chemical elements. Life Hinrichs was born in 1836 in Lunden in the Duchy of Holstein, which at that time was under the rule of Denmark although it was simultaneously part of the German Confederation. He attended the local polytechnic school and the University of Copenhagen. During his schooling he published several articles and books, including descriptions of the magnetic field of earth and its interaction with the aether. Hinrichs graduated in 1860, between the First and Second Schleswig Wars. He emigrated later that year to the United States, settling initially in Davenport, Iowa, where he taught school, then in nearby Iowa City. In 1863 he was appointed a professor of natural philosophy, chemistry, and modern languages at the University of Iowa. He founded the first state weather and crop service in the United ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
