© REGION 4 EDUCATION SERVICE CENTER. ALL RIGHTS RESERVED.
65
© REGION 4 EDUCATION SERVICE CENTER. ALL RIGHTS RESERVED.
65
Lesson 8: Analyzing Chemical Formulas
Explain, Part 1
Review the
Explore card matching activity in a class discussion.
What do the letters represent?
What is the total number of shapes on each card?
Explain, Part 2
Analyzing Chemical Formulas
All compounds have definite compositions that can be represented by a chemical
formula. Remember that chemical formulas use symbols or a combination of
symbols and subscripts to show the
elements and the number of atoms of each
element that make up the molecule.
For example, the formula for oxygen gas is O
2
. The subscript indicates two oxygen
atoms are bonded in an oxygen molecule as shown in Figure 2.32.
Figure 2.32. Oxygen Molecule
O O
Another common chemical formula is H
2
O. As shown in Figure 2.33, H
2
represents 2
atoms of hydrogen and O represents 1 atom of oxygen. H
2
O is the chemical formula
for the inorganic compound known as water.
Figure 2.33. Molecule of Water
H H
O