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Representing Chemical Bonds Polyatomic Ions. Formulas Names. Polyatomic Ions. A group of covalently bonded atoms that has a positive or negative charge that acts as one unit Examples (list on pg. 158):. Hydroxide: OH - Sulfate: SO 4 2- NO 3 - : Nitrate CO 3 2- : Carbonate.
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Representing Chemical BondsPolyatomic Ions Formulas Names
Polyatomic Ions • A group of covalently bonded atoms that has a positive or negative charge that acts as one unit • Examples (list on pg. 158): Hydroxide: OH- Sulfate: SO42- NO3-: Nitrate CO32-: Carbonate Ammonium: NH4+ Peroxide: O22- PO43-: Phosphate
Formulas for Compounds with Polyatomic Ions • All atoms in a polyatomic ion need to be written, but the charge comes with the ENTIRE GROUP • The charge is not assigned to one specific atom in the group, but the group as a whole • If more than one group is needed, the formula for the polyatomic ion is written in parentheses and the subscript is written outside of the parentheses • Ba(OH)2
Naming Compounds with Polyatomic Ions • Name of cation comes first • Rule is the same if ammonium ion is the cation • (NH4)2O → “ammonium oxide” • Anion name comes second • If anion is polyatomic, name is written as is • No changing the end to “ide” • Na2SO4 → “sodium sulfate” • Ba(OH)2 → “barium hydroxide”