Day 8 ­ Polyatomic compounds.notebook
Chemistry Day 8 Part 2:
Polyatomic Compounds
Learning Goals:
September 21, 2016
Minds On: Draw Lewis diagrams for the formation of the following
ionic compounds.
a) Calcium Fluoride
b) Aluminum Sulfide
By the end of today I can:
• Define Polyatomic ions
• Name a polyatomic ion given the formula
• Write the formula for a polyatomic ion given the name
• Write the name and chemical formula for polyatomic compounds
Oct 28­7:03 PM
Polyatomic compounds are "salts" made of more than two
elements. They are normally composed of a metal and polyatomic
ion group. The exception to this is when hydrogen is grouped with a
polyatomic ion to form an acid.
Sep 21­8:31 AM
Success Criteria for Naming and Writing the Formula for Polyatomic Compounds
Formula
Naming
Ca(NO3)2
1) Write the name of the metal
2) Write the name of the
Potassium Phosphate
1) Find the symbol and common ion
charge of the metal
2) Find the symbol and ion charge
polyatomic ion
for the polyatomic ion
3) Put the two names together
with the name of the metal
3) Balance out the charges by
using the criss-cross rule to find
first
the subscripts needed in the
formula
Oct 28­7:41 PM
Mar 13­10:00 AM
Examples:
Oxyanions: Most polyatomic compounds have oxygen as a
Write the name for the following compounds:
part of their grouping. These anions have special naming
a) NaClO3
b) MgSO4
c) K3PO4
rules for when the number of oxygens in the group change.
Number of
Write the chemical formula for the following compounds:
a) Sodium Nitrate b) Calcium Chlorate c) Magnesium Phosphate
Oct 3­1:32 PM
Oxygen
name change
example
+1
per...ate
normal
...ate
perchlorate
-1
...ite
chlorite
-2
hypo...ite
hypochlorite
chlorate
Sep 21­8:31 AM
1
Day 8 ­ Polyatomic compounds.notebook
September 21, 2016
Practice:
Name the following:
a) K2SO2
b) Mg3(PO5)2
c) NaClO
d) Ba(NO3)2
Write formulas for the following compounds:
a) Calcium Sulfite
b) Copper (II) Hypophosphite
c) Iron (III) Perchlorate c) Sodium Borite
Sep 21­8:37 AM
2