1. Polyatomic Ions
Lesson 7

2. Monatomic Ions
Ions that are composed of one atom are called monatomic ions.
Monoatomic Ion- an ion composed of only one atom.
We have only looked at these so far

3. Polyatomic Ions
Polyatomic Ions are ions that are composed of more than one atom. The entire molecule carries a charge to it.

4. Polyatomic Ions
Example-
NO3-
SO42-
PO43-

5. Bonding
Ionic Bonding with polyatomic ions occurs in the same manner as it does with binary atomic molecules.
Use the crossover method
Be sure that the charge that is crossed over applies to the whole polyatomic ion. If the charge is greater than 1, use brackets around the polyatomic ion to indicate the number applies to the whole ion.

6. Example 1 Sodium nitrate Step 1 Na + NO3- Step 2 1+ 1- Na NO3 Step 3
Na NO3
Step 3
Step 4
NaNO3
Sodium nitrate

7. Example 2 Magnesium nitrate Step 1 Mg + NO3- Step 2 2+ 1- Mg NO3
Mg NO3
Step 3
Step 4
Mg (NO3)2
Magnesium nitrate

8. Practice
Mg + ClO3- =
Na + SiO32- =
Fr + HS- =
NH4+ + Cl =
Li + Cl =
Be + O22- =
Sr + PO43- =
Al + BO33- =
Al + SO42- =
Na + OH- =

9. Naming Ionic Polyatomic compounds: IUPAC
Multivalent: Metal (charge) polyatomic ion
Monovalent: Metal polyatomic ion
Tertiary ionic compounds are comprised of a metal ion and a polyatomic ion. Write the polyatomic ions in the same way as monatomic ions.

10. Examples NaOH = Cu(ClO3)2 = Tin (IV) chlorate =
sodium hydroxide (NOT MULTIVALENT)
Cu(ClO3)2 =
copper (II) chlorate
Tin (IV) chlorate =
Sn (ClO3)4

11. NOTE: Look at the resource page, notice the *
This means that bromine and iodine will have the same ending if there are the same number of oxygen's as the chlorine.

12. Oxyanions = a polyatomic ion that includes oxygen
Their name depends on how many Oxygen’s it has in the poly atomic ion. (Cl, I and Br share the same prefixes and suffixes for the same # of oxygens)
Example
ClO- hypochlorite ion hypo-_________-ite
ClO2- chlorite ion __________-ite
ClO3- chlorate ion __________-ate
ClO4- perchlorate ion per-_______-ate­
Iod or Bor
Iod or Bor
Iod or Bor
Iod or Bor

13. Practice
Do the questions on the note.