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  2. Chemical impurity - Wikipedia

    en.wikipedia.org/wiki/Chemical_impurity

    An example of when impurities are wanted is shown in gems. These gems have slight impurities that act as chromophores and give the stone its color. An example is the gem family beryl which has the base chemical formula of Be 3 Al 2 (SiO 3) 6. Pure beryl will appear colorless but this rarely occurs and the presence of trace elements change its ...

  3. List of purification methods in chemistry - Wikipedia

    en.wikipedia.org/wiki/List_of_purification...

    Electrolysis refers to the breakdown of substances using an electric current. This removes impurities in a substance that an electric current is run through; Sublimation is the process of changing of any substance (usually on heating) from a solid to a gas (or from gas to a solid) without passing through liquid phase. In terms of purification ...

  4. Chemical substance - Wikipedia

    en.wikipedia.org/wiki/Chemical_substance

    Some chemical substances can be combined or converted into new substances by means of chemical reactions. Chemicals that do not possess this ability are said to be inert. Pure water is an example of a chemical substance, with a constant composition of two hydrogen atoms bonded to a single oxygen atom (i.e. H 2 O).

  5. Material - Wikipedia

    en.wikipedia.org/wiki/Material

    A material is a substance or mixture of substances that constitutes an object.Materials can be pure or impure, living or non-living matter. Materials can be classified on the basis of their physical and chemical properties, or on their geological origin or biological function.

  6. Chemical purity - Wikipedia

    en.wikipedia.org/wiki/Chemical_purity

    The examples and perspective in this article deal primarily with American designations and do not represent a worldwide view of the subject. You may improve this article, discuss the issue on the talk page, or create a new article, as appropriate. (January 2022) (Learn how and when to remove this message)

  7. Contamination - Wikipedia

    en.wikipedia.org/wiki/Contamination

    Within the sciences, the word "contamination" can take on a variety of subtle differences in meaning, whether the contaminant is a solid or a liquid, [3] as well as the variance of environment the contaminant is found to be in. [2] A contaminant may even be more abstract, as in the case of an unwanted energy source that may interfere with a process. [2]

  8. Mixture - Wikipedia

    en.wikipedia.org/wiki/Mixture

    It's an impure substance made up of 2 or more elements or compounds mechanically mixed together in any proportion. [1] A mixture is the physical combination of two or more substances in which the identities are retained and are mixed in the form of solutions, suspensions or colloids. [2] [3]

  9. Chemical compound - Wikipedia

    en.wikipedia.org/wiki/Chemical_compound

    Many solid chemical substances—for example many silicate minerals—are chemical substances, but do not have simple formulae reflecting chemically bonding of elements to one another in fixed ratios; even so, these crystalline substances are often called "non-stoichiometric compounds".