Practice with Chemical Formulas

By Mr. Cranston

Practice with Chemical Formulas

Practice with Chemical Formulas: Subscripts

Subscripts tell you the number of atoms.

Practice with Chemical Formulas: Subscripts

Subscripts always follow the element.

Practice with Chemical Formulas: Subscripts

If there's no subscript, there's only one atom.

Multiple Choice

Ozone is $$O_3$$  . How many oxygen atoms does it have?

• 1

• 2

• 3

• 4

Multiple Choice

Rust is $$Fe_2O_3$$  . How many oxygen atoms does it have?

• 1

• 2

• 3

• 4

Multiple Choice

Glucose is $$C_6H_{12}O_6$$  . How many hydrogen atoms does it have?

• 6

• 8

• 12

• 18

Multiple Choice

Methanol is $$CH_4O$$  . How many oxygen atoms does it have?

• 0

• 1

• 4

• 6

Help with Chemical Formulas: Subscripts

Coefficients tell you the number of molecules. If there's no coefficient, there's only 1 molecule.

Multiple Choice

How many carbon dioxide molecules? $$3CO_2$$  

• 1

• 2

• 3

• 4

Multiple Choice

How many oxygen gas molecules?

$$2Mg\ +\ O_2\ \rightarrow\ 2MgO$$  

• 0

• 1

• 2

• 4

Here are some more questions to help you solidify your understanding.

More Practice

Multiple Choice

How many nitrogen (N) atoms are in laughing gas?

$$N_2O$$  

• 0

• 1

• 2

• 3

Multiple Choice

How many sulfur (S) atoms are there in sulfuric acid?

$$H_2SO_4$$  

• 0

• 1

• 2

• 4

Multiple Choice

How many water molecules are produced?

$$O_2\ +2H_2\ \rightarrow\ 2H_2O$$  

• 0

• 1

• 2

• 4

Multiple Choice

How many oxygen gas molecules react?

$$O_2\ +2H_2\ \rightarrow\ 2H_2O$$  

• 0

• 1

• 2

• 4

Multiple Choice

How many hydrogen gas molecules react?

$$O_2\ +2H_2\ \rightarrow\ 2H_2O$$  

• 0

• 1

• 2

• 4

Multiple Choice

How many total hydrogen atoms react?

$$O_2\ +2H_2\ \rightarrow\ 2H_2O$$  

• 0

• 1

• 2

• 4

Multiple Choice

How many total oxygen atoms are on the right side of the equation?

$$O_2\ +2H_2\ \rightarrow\ 2H_2O$$  

• 0

• 1

• 2

• 4