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Reactive Nonmetals
In chemistry, after Nonmetal (chemistry), nonmetallic elements such as silicon, chlorine, and helium are classed as either metalloids, halogens, or noble gases, the remaining unclassified nonmetallic elements are hydrogen, carbon, nitrogen, oxygen, phosphorus, sulfur and selenium. The nonmetallic elements are sometimes instead divided into two to seven alternative classes or sets according to, for example, electronegativity; the relative homogeneity of the halogens; molecular structure; the peculiar nature of hydrogen; the corrosive nature of oxygen and the halogens; their respective groups; and variations thereupon. Classification science Classes provided an economy of description and are beneficial to structuring knowledge and understanding of science. The distinction between classes is not absolute. Boundary overlaps can occur as outlying elements in each class show or begin to show less-distinct, hybrid-like, or atypical properties. As expressed by Nelson: :"…care needs to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boron R105
Boron is a chemical element; it has Chemical symbol, symbol B and atomic number 5. In its crystalline form it is a brittle, dark, lustrous metalloid; in its Amorphous solid, amorphous form it is a brown powder. As the lightest element of the boron group it has three valence electrons for forming covalent bonds, resulting in many compounds such as boric acid, the mineral borax, sodium borate, and the ultra-hard crystals of boron carbide and boron nitride. Boron is synthesized entirely by cosmic ray spallation and supernovas and not by stellar nucleosynthesis, so it is a low-abundance element in the Solar System and in the Crust (geology), Earth's crust. It constitutes about 0.001 percent by weight of Earth's crust. It is concentrated on Earth by the water-solubility of its more common naturally occurring compounds, the borate minerals. These are mined industrially as evaporites, such as borax and kernite. The largest known deposits are in Turkey, the largest producer of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbon
Carbon () is a chemical element; it has chemical symbol, symbol C and atomic number 6. It is nonmetallic and tetravalence, tetravalent—meaning that its atoms are able to form up to four covalent bonds due to its valence shell exhibiting 4 electrons. It belongs to group 14 of the periodic table. Carbon makes up about 0.025 percent of Earth's crust. Three Isotopes of carbon, isotopes occur naturally, carbon-12, C and carbon-13, C being stable, while carbon-14, C is a radionuclide, decaying with a half-life of 5,700 years. Carbon is one of the timeline of chemical element discoveries#Pre-modern and early modern discoveries, few elements known since antiquity. Carbon is the 15th abundance of elements in Earth's crust, most abundant element in the Earth's crust, and the abundance of the chemical elements, fourth most abundant element in the universe by mass after hydrogen, helium, and oxygen. Carbon's abundance, its unique diversity of organic compounds, and its unusual abi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Field
Field may refer to: Expanses of open ground * Field (agriculture), an area of land used for agricultural purposes * Airfield, an aerodrome that lacks the infrastructure of an airport * Battlefield * Lawn, an area of mowed grass * Meadow, a grassland that is either natural or allowed to grow unmowed and ungrazed * Playing field, used for sports or games Arts and media * In decorative art, the main area of a decorated zone, often contained within a border, often the background for motifs ** Field (heraldry), the background of a shield ** In flag terminology, the background of a flag * ''FIELD'' (magazine), a literary magazine published by Oberlin College in Oberlin, Ohio * ''Field'' (sculpture), by Anthony Gormley Organizations * Field department, the division of a political campaign tasked with organizing local volunteers and directly contacting voters * Field Enterprises, a defunct private holding company ** Field Communications, a division of Field Enterprises * Field Museu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diatomic Nonmetal
In the context of the periodic table, a nonmetal is a chemical element that mostly lacks distinctive metallic properties. They range from colorless gases like hydrogen to shiny crystals like iodine. Physically, they are usually lighter (less dense) than elements that form metals and are often poor conductors of heat and electricity. Chemically, nonmetals have relatively high electronegativity or usually attract electrons in a chemical bond with another element, and their oxides tend to be acidic. Seventeen elements are widely recognized as nonmetals. Additionally, some or all of six borderline elements (metalloids) are sometimes counted as nonmetals. The two lightest nonmetals, hydrogen and helium, together account for about 98% of the mass of the observable universe. Five nonmetallic elements—hydrogen, carbon, nitrogen, oxygen, and silicon—form the bulk of Earth’s atmosphere, biosphere, crust and oceans, although metallic elements are believed to be slightly more tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bettelheim2016
Bettelheim is a surname and Jewish family. History The first bearer of the Bettelheim name is said to have lived toward the second half of the 18th century, in Pressburg (Pozsony, today Bratislava). To account for its origin, the following episode is related in the family records: There was a Jewish merchant in Bratislava (now in Slovakia) (before Pozsony), whose modest demeanor gained for him the esteem of his fellow-townsmen. He was popularly called ''"Ein ehrlich Jud"'' (honest Jew). His wife was a woman of surpassing beauty, and many magnates of the country, hearing of her charms, traveled to Pozsony to see her. Count Bethlen was particularly persistent, and, failing to attract her attention, he decided to abduct her. Mounted on his charger, he appeared one day in the open market, where the virtuous woman was making purchases, and in the sight of hundreds of spectators, lifted her on his horse, and heedless of her cries of entreaty, was about to gallop off with her, when he ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nelson
Nelson may refer to: Arts and entertainment * ''Nelson'' (1918 film), a historical film directed by Maurice Elvey * ''Nelson'' (1926 film), a historical film directed by Walter Summers * ''Nelson'' (opera), an opera by Lennox Berkeley to a libretto by Alan Pryce-Jones * Nelson (band), an American rock band * ''Nelson'', a 2010 album by Paolo Conte People * Nelson (surname), including a list of people with the name * Nelson (given name), including a list of people with the name * Horatio Nelson, 1st Viscount Nelson (1758–1805), British admiral * Nelson Mandela, the first black South African president * Bishop of Nelson (other), a title sometimes referred to as "Nelson" Fictional characters * Alice Nelson, the housekeeper on the TV series ''The Brady Bunch'' * Dave Nelson, a main character on the TV series ''NewsRadio'' * Emma Nelson (Degrassi: The Next Generation), on the TV series ''Degrassi: The Next Generation'' * Foggy Nelson, law partner of Matt Murdock in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jones2010
Jones or Joneses may refer to: People and fictional characters *Jones (surname), a common Welsh and English surname * List of people with surname Jones, including fictional characters ** Justice Jones (other) ** Judge Jones (other) * Jones (singer), a British singer-songwriter * Jones of Faerdref Uchaf, a Welsh noble family * Generation Jones, the generation of people born between 1954 and 1965 * Jones (''Animal Farm''), a human character in George Orwell's novel ''Animal Farm'' Places * Jones (Martian crater), an impact crater on Mars * Jones, Ontario, Canada * Jones, Isabela, Philippines * Banton, Romblon, Philippines (formerly as ''Jones'') United States * Jones, Alabama * Jones, Illinois * Jones, Kentucky * Jones, Michigan * Jones, Oklahoma *Jones, West Virginia *Jones Township (other) Arts and entertainment * "Jones" (''Law & Order: Criminal Intent''), an episode of the TV series *"Jones", a song from the album '' Certain Things Are Likely'' by Ki ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electronegativity
Electronegativity, symbolized as , is the tendency for an atom of a given chemical element to attract shared electrons (or electron density) when forming a chemical bond. An atom's electronegativity is affected by both its atomic number and the distance at which its valence electrons reside from the charged nucleus. The higher the associated electronegativity, the more an atom or a substituent group attracts electrons. Electronegativity serves as a simple way to quantitatively estimate the bond energy, and the sign and magnitude of a bond's chemical polarity, which characterizes a bond along the continuous scale from covalent to ionic bonding. The loosely defined term electropositivity is the opposite of electronegativity: it characterizes an element's tendency to donate valence electrons. On the most basic level, electronegativity is determined by factors like the nuclear charge (the more protons an atom has, the more "pull" it will have on electrons) and the number and lo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Selenium
Selenium is a chemical element; it has symbol (chemistry), symbol Se and atomic number 34. It has various physical appearances, including a brick-red powder, a vitreous black solid, and a grey metallic-looking form. It seldom occurs in this elemental state or as pure ore compounds in Earth's crust. Selenium ( ) was discovered in 1817 by , who noted the similarity of the new element to the previously discovered tellurium (named for the Earth). Selenium is found in :Sulfide minerals, metal sulfide ores, where it substitutes for sulfur. Commercially, selenium is produced as a byproduct in the refining of these ores. Minerals that are pure selenide or selenate compounds are rare. The chief commercial uses for selenium today are glassmaking and pigments. Selenium is a semiconductor and is used in photocells. Applications in electronics, once important, have been mostly replaced with silicon semiconductor devices. Selenium is still used in a few types of Direct current, DC power surge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfur
Sulfur ( American spelling and the preferred IUPAC name) or sulphur ( Commonwealth spelling) is a chemical element; it has symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms form cyclic octatomic molecules with the chemical formula S8. Elemental sulfur is a bright yellow, crystalline solid at room temperature. Sulfur is the tenth most abundant element by mass in the universe and the fifth most common on Earth. Though sometimes found in pure, native form, sulfur on Earth usually occurs as sulfide and sulfate minerals. Being abundant in native form, sulfur was known in ancient times, being mentioned for its uses in ancient India, ancient Greece, China, and ancient Egypt. Historically and in literature sulfur is also called brimstone, which means "burning stone". Almost all elemental sulfur is produced as a byproduct of removing sulfur-containing contaminants from natural gas and petroleum.. Downloahere Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
