Contrast molecular compounds which are contrast which

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Contrast molecular compounds , which are Contrast , which are formed from combinations of nonmetals only (H 2 O, CO 2 , CH 4 , etc.) bonded by shared , etc.) bonded by shared electron pairs in a “covalent bond” Combinations of metalloids and nonmetals S. Ensign, Atomic structure & nomenclature 55 S. Ensign, Chem. 1210 Combinations of metalloids and nonmetals are usually classified as “molecular” Reaction of Na and Cl Ionic compounds are always represented by empirical formulas: there is no discrete molecular formula for an ionic S. Ensign, Atomic structure & nomenclature 56 formulas: there is no discrete molecular formula for an ionic solid
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Writing empirical formulas for ionic compounds A d i h l 2 l i “bi A compound with only 2 elements is a “binary compound” F i i d l th b l f th For ionic compounds, place the symbol for the metal before that of the nonmetal (cation first, anion second) Subscripts after the elements designate the number of atoms of that type in the compound When writing the formula of a neutral ionic compound, net charge = 0, so the charges must compound, net charge 0, so the charges must balance for each ion S. Ensign, Atomic structure & nomenclature 57 Writing empirical formulas for ionic compounds A compound with only 2 elements is a “binary A compound with only 2 elements is a binary compound” For ionic compounds, place the symbol for the metal before that of the nonmetal (cation first, anion second) Subscripts after the elements designate the number of atoms of that type in the compound When writing the formula of a neutral ionic compound, net charge = 0, so the charges must balance for each ion S. Ensign, Atomic structure & nomenclature 58 Writing empirical formulas for ionic compounds A compound with only 2 elements is a “binary A compound with only 2 elements is a binary compound” For ionic compounds, place the symbol for the metal before that of the nonmetal (cation first, anion second) Subscripts after the elements designate the number of atoms of that type in the compound When writing the formula of a neutral ionic compound, net charge = 0, so the charges must balance for each ion S. Ensign, Atomic structure & nomenclature 59 Polyatomic ions: a compound of two or more nonmetal atoms joined through more nonmetal atoms, joined through covalent bonds, that forms a single charged unit (i e a molecular compound charged unit (i.e., a molecular compound that does not have a neutral charge) ¾ SO 3 is a molecular compound ¾ SO 4 2- is a polyatomic anion ¾ NH 3 is a molecular compound ¾ NH 4 + is a polyatomic cation S. Ensign, Atomic structure & nomenclature 60
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