Polyatomic Ions
Lesson 8
Chemistry 10
Objective: You will be able to
-identify ions that are polyatomic
-name these ions
-write chemical formulas for compounds that form
with these ions.
What is a polyatomic ion?
Look at the diagram below. What kind of things
do you notice?
Periodic table and these ions
A table of polyatomic ions is on the back of your
periodic table. Locate this table, read it and make
note of things you notice that might let us identify
these ions.
Using these ions in ionic compounds
These ions are bonded together by a very strong
force. They will not break apart when combining
with metallic ions to form a compound.
Example: SO42- is a very stable ion. It stays
together. When it is reacted with a sodium ion, it
forms an ionic compound. Write the formula for
this compound.
Examples
Try writing the formula for these compounds.
1. calcium nitrate
2. copper (II) sulfate
3. barium hydroxide
4. calcium hydrogen carbonate
Naming
Naming is exactly the same as for all other ionic
compounds. Metal-nonmetal
Examples:
1. Sr3(PO4)2 (s)
2. CuSO4(s)
Assignment
Polyatomic Worksheet p. 4
Reading p. 44 - 46