© REGION 4 EDUCATION SERVICE CENTER. ALL RIGHTS RESERVED.
67
© REGION 4 EDUCATION SERVICE CENTER. ALL RIGHTS RESERVED.
67
Lesson 8: Analyzing Chemical Formulas
Explain, Part 3
Using Coef cients and Subscripts
A coefficient indicates the number of molecules of a compound or element. For
example, 6 molecules of water is written as 6H
2
O.
Figure 2.35. Parts of a Compound
6H
2
O
Coefficient—There are 6
molecules of water.
Subscript—There are
2 atoms of hydrogen in
each of the 6 molecules of
water.
No subscript—There is
only 1 atom of oxygen in
each of the 6 molecules of
water.
A visual can also be used to help determine the total number of atoms. The
coefficient indicates there are 6 molecules of water.
Figure 2.36. Visual Model of a Compound
H H
O
H H
O
H H
O
H H
O
H H
O
H H
O
Here’s another way to determine the number of atoms of each element:.
To determine the number of atoms in 6H
2
O:
6 molecules x 2 hydrogen atoms = 12 hydrogen atoms
6 molecules x 1 oxygen atom = 6 oxygen atoms