Counting Atoms in Chemical Formulas

Counting Atoms in Chemical Formulas

Read each chemical formula carefully and determine the number of atoms for each element present. Write your answers in the spaces provided.

1. H₂O

Hydrogen (H):   Oxygen (O):  

2. CO₂

Carbon (C):   Oxygen (O):  

3. NaCl

Sodium (Na):   Chlorine (Cl):  

4. C₆H₁₂O₆

Carbon (C):   Hydrogen (H):   Oxygen (O):  

1. Ca(OH)₂

Calcium (Ca):   Oxygen (O):   Hydrogen (H):  

2. Al₂(SO₄)₃

Aluminum (Al):   Sulfur (S):   Oxygen (O):  

3. Mg(NO₃)₂

Magnesium (Mg):   Nitrogen (N):   Oxygen (O):  

1. 2H₂O

Hydrogen (H):   Oxygen (O):  

2. 3CO₂

Carbon (C):   Oxygen (O):  

3. 4NaCl

Sodium (Na):   Chlorine (Cl):  

1. 2Ca(OH)₂

Calcium (Ca):   Oxygen (O):   Hydrogen (H):  

2. 3Al₂(SO₄)₃

Aluminum (Al):   Sulfur (S):   Oxygen (O):  

3. 5Mg(NO₃)₂

Magnesium (Mg):   Nitrogen (N):   Oxygen (O):  

1. In the formula C₃H₈, there are 3 carbon atoms and 8 hydrogen atoms.

2. The formula 2KCl indicates a total of 2 potassium atoms and 2 chlorine atoms.