1. Polyatomic Ions Lesson 2
Many atoms with a charge.
Example (SO4)-2
Blue sheet

2. O Zn N NO3 NO3 Zn NO3 Zn(NO3)2 Zn -1 -1 -1 +2 +2 +1 -1 +4 IA +2 +3 -4+4 IA
VIIA
VIIIA +2 +3 -4 -3 -2
IIA
Zinc = +2
IIIA
IVA VA
VIA

3. Now called Iron(III) sulfateFe
SO4 -2
SO4 -2 Fe +3
SO4 -2 Fe +3 -2
SO4
Fe2(SO4)3 Fe +3 +1 -1 +4 IA
VIIA
VIIIA +2 +3 -4 -3 -2
IIA
IIIA
IVA VA
VIA
Now called Iron(III) sulfate
Iron=+3

4. Polyatomic Ion Formulas
Concept:
Polyatomic ions are groups of atoms that behave as one unit.
Fact 4:
Some ions have more that one atom but their overall charge can be determined.
Examples: (SO4) = S +6 and O -8 = -2
(NO3)= N +5 and O -6 = -1
(NH4) = N -3 and H +4 = +1

5. Polyatomic Ion Formulas
Fact 5: These group ions, polyatomic ions, are treated like single ions in formulas, but must have parentheses when more than one is used in a formula.
Examples: Ca2+(NO3) 1- ====
Ga3+ (SO4) 2- ===
(NH4) 1+2O ====

6. Polyatomic Ion Formulas
Fact 6:
The polyatomic ions are named based on the atoms that they contain. Those with oxygen and another nonmetal are often name "____ate" with the root of the other nonmetal in the blank.
Examples: (NO3)1- is ______________
(SO4)2- _______________
(ClO3) 1- _______________

7. Polyatomic Ion Formulas
Fact 7:
Those polyatomic ions with one oxygen less than the "ate" ions are named "----ite" ions.
Examples: (NO2) is nitrite
(SO3)2- is ____________
(ClO2)1- is _____________

8. Examples - Formulas to Names
1. Write the names of the ions
2. Determine the charge of the positive ion
I’m a polyatomic ion
Ba(ClO4)2
barium
perchlorate
If the positive ion has a fixed charge, you are finished.
Final Name