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chemical elementelement,
in chemistry, a substance that cannot be decomposed into simpler substances by chemical means. A substance such as a compound can be decomposed into its constituent elements by means of a chemical reaction, but no further simplification can be achieved.
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 possessing certain properties by which it is distinguished from a metalmetal,
chemical element displaying certain properties by which it is normally distinguished from a nonmetal, notably its metallic luster, the capacity to lose electrons and form a positive ion, and the ability to conduct heat and electricity.
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. In general, this distinction is drawn on the basis that a nonmetal tends to accept electrons and form negative ionsion,
atom or group of atoms having a net electric charge. Positive and Negative Electric Charges

A neutral atom or group of atoms becomes an ion by gaining or losing one or more electrons or protons.
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 and that its oxide is acidic. Nonmetals are poor conductors of heat and electricity (see conductionconduction,
transfer of heat or electricity through a substance, resulting from a difference in temperature between different parts of the substance, in the case of heat, or from a difference in electric potential, in the case of electricity.
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) and do not have the luster of metals. Arsenic, antimony, selenium, and tellurium exhibit both nonmetallic and metallic properties and are called metalloids. Unlike the metals, which are all solids (with the exception of mercury) under ordinary conditions of temperature and pressure, the nonmetals appear in all three states. Argon, chlorine, fluorine, helium, hydrogen, krypton, neon, nitrogen, oxygen, and xenon are normally gases. Bromine is a liquid. Boron, carbon, iodine, phosphorus, silicon, and sulfur are solids. Certain of them, e.g., boron, carbon, iodine, silicon, and sulfur, form crystals, as do the metals. In hardness they vary considerably. Carbon in its allotropic form, the diamond, is the hardest element known. With the exception of carbon, sulfur, nitrogen, oxygen, and the inert gases—argon, helium, krypton, neon, and xenon—the nonmetals do not occur uncombined in nature, but exist in numerous relatively abundant compounds, among which are the oxides, halides (binary halogen compounds), sulfides, carbonates, nitrates, phosphates, silicates, and sulfates. With a few exceptions, the nonmetallic elements are important chiefly for their compounds. For the properties and uses of specific nonmetals, see the separate articles on these elements.


any of a number of chemical elements that form negative ions, have acidic oxides, and are generally poor conductors of heat and electricity
References in periodicals archive ?
These pieces of non-metal cutlery, could pose as alternatives to traditional metal knives.
Johnson knew that laser cutting is not always the best tool for some jobs and was interested in purchasing a waterjet cutting system for certain high-precision jobs and non-metal cutting.
Spinal implants are based on both metal and non-metal materials.
The conditions in this level include uncomplicated metal shapes (no non-metal substrates of significance); few colors to meet most of demand; the level of smoothness (orange peel, appearance) was acceptable; relatively wide variations of dry film thicknesses were ok--1.
Threats--foreign competition, plastics and other non-metal processes, powdered metals, fabrications, forgings, the industry's reactive rather than proactive nature.
Used to measure coating thickness on wood, concrete, plastic, and other non-metal substrates, the new PosiTector 200 integrates the advanced features, graphing capabilities, and increased range of the PosiTector 100 and is available in either Standard or Advanced models.
A direct-to-metal coating for pipes, tanks and other metallic substrates, Nansulate GP is a general purpose formulation designed for wood, fiberglass and other non-metal substrates.
All Boeing 737 planes - the model which carries millions of tourists to their destinations each year -will be constructed from a combination of non-metal materials known as composites, the plane-maker said.
In the future more aircraft will be made from non-metal materials, or composites, according to Alan Mulally, the chief executive of Boeing Commercial Airplanes.
Accent's technology will also strengthen our position in optical CD and non-metal thin film metrology.
Many other general product suppliers also paid kickbacks to sell steel and iron to Iraq, but payments were bundled with money to secure contracts for a wide range of cargo, including non-metal items.

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