Element - Pure substances that are made of only one type of atom. Usually contains many atoms of the same type, Compound - Two or more different substances chemically combined, Mixture - Two or more different substances that are not chemically combined. May cotain elements or compounds, molecule - Two or more atoms chemically combined with a fixed amount of atoms, lattice - contains more than one atom but it doesn't have a fixed amount of atoms and can be expanded easily with more atoms. , Atom - A single unit of an element. ,

its elementary

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