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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] |
