Two or more elements bonded together and acting as one ion Polyatomic Ions Two or more elements bonded together and acting as one ion

The charge is for the whole polyatomic ion, not just the last element. Ex: OH- (hydroxide) Oxygen needs 2 to complete the octet, has 2- ionization number Hydrogen has one electron to give away, has 1+ ionization number (2-) + (1+) = 1- so hydroxide is OH-

-ite vs -ate NO2- nitrite NO3 - nitrate SO3 2- sulfite SO4 2- sulfate ite has fewer oxygens NO2- nitrite SO3 2- sulfite ate has more oxygens NO3 - nitrate SO4 2- sulfate

Naming the ate ions NICK the CAMEL Ate CLAM for SUPPER in PHOENIX Underlined letter is the symbol Number of consonants is the number of oxygens Number of vowels is the number of the negative charge on the ion

NICK NO3 - nitrate N = nitrogen 3 consonants = oxygens 1 vowel = charge NO3 - nitrate

CAMEL CO3 2- carbonate C = carbon 3 consonants = oxygens 2 vowels = charge CO3 2- carbonate

CLAM Cl3 - chlorate Cl = chlorine 3 consonants = oxygens 1 vowel = charge Cl3 - chlorate

SUPPER SO4 2- sulfate S = Sulfur 4 consonants = oxygens 2 vowels = charge SO4 2- sulfate

PHOENIX P = phosphorus 4 consonants = oxygens 3 vowels = charge PO4 3- phosphate