Download Ionic vs Molecular and Count Atoms

Molecular
vs
Ionic Compounds
Molecular compounds
are made of two or more
NON-METAL elements
Example:
SO4
Ionic compounds are made of
METAL and NON-METAL
elements
Example:
NaCl
Ionic or Molecular?
Molecular = 2 non-metal elements
Ionic = metal & non-metal elements
Ionic or Molecular?
Molecular = 2 non-metal elements
Ionic = metal & non-metal elements
Ionic or Molecular?
Molecular = 2 non-metal elements
Ionic = metal & non-metal elements
How to
Count
Atoms
•The little numbers at the bottom of
element symbols tells us how
many atoms there are
• Example:
F2 There are two F atoms
This little number is
called a subscript
IF AN ATOM DOES NOT HAVE A
NUMBER BEHIND, IT IS ALWAYS
ONE
• Example:
Cl
There is one Cl atom
no subscript
means 1 atom
How many atoms of each?
H2O
2 H’s
1O
How many atoms of each?
P 2O 3
2 P’s
3 O’s
How many atoms of each?
KNO3
1K
1N
3 O’s
How many atoms of each?
6 C’s
C6H12O6 12 H’s
6 O’s
What is the chemical formula?
What is the chemical formula?
What is the chemical formula?
What is the chemical formula?
What is the chemical formula?
This big number is
called a coefficient
How many atoms of each?
2HCl
2 H’s
2 Cl’s
How many atoms of each?
4H2O
8 H’s
4 O’s
How many atoms of each?
3C2H4
6 C’s
12 H’s
How many atoms of each?
3HPO4
3 H’s
3P’s
12 O’s
Brackets with Subscripts
A subscript number OUTSIDE the
bracket must be multiplied by ALL
atoms INSIDE the bracket
• Example:
(NO3)2
2 N’s
6 O’s
How many atoms of each?
(SeO4)3
3 Se’s
12 O’s
How many atoms of each?
(MnO4)2
2 Mn’s
8 O’s
How many atoms of each?
(HPO4 )3
3 H’s
3 P’s
12 O’s
Coefficients Outside of Brackets
The coefficient applies to ALL atoms
inside and outside the bracket
• Example:
4(NO3)2
4(NO3)2
1N
3 O’s
4(NO3)2
1 x 2 = 2 N’s
3 x 2 = 6 O’s
4(NO3)2
2 x 4 = 8 N’s
6 x 4 = 24 O’s
How many atoms of each?
Al(NO3)3
1 Al
3 N’s
9 O’s
How many atoms of each?
2 Cl
2Cl(H2O)3 12 H’s
6 O’s