Question

A ________ is presented by a chemical ____

Answer 1

Answer:

chemical substance is a form of matter having constant chemical composition and characteristic properties.[1][2] Some references add that chemical substance cannot be separated into its constituent elements by physical separation methods, i.e., without breaking chemical bonds.[3] Chemical substances can be simple substances,[4] chemical compounds, or alloys. Chemical elements may or may not be included in the definition, depending on expert viewpoint.[4]

Answer 2

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Chemical reaction, a process in which one or more substances, the reactants, are converted to one or more different substances, the products. Substances are either chemical elements or compounds. A chemical reaction rearranges the constituent atoms of the reactants to create different substances as products.....

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