Counting Atoms in Chemical Formulas
This worksheet helps Grade 11 students practice counting atoms in various chemical formulas, including those with subscripts, coefficients, and parentheses.
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Counting Atoms in Chemical Formulas
Name:
Date:
Score:
Read each chemical formula carefully and determine the number of atoms for each element present. Show your work where indicated.
1. In H₂O, there are hydrogen atoms and oxygen atoms.
2. For CO₂, there is carbon atom and oxygen atoms.
3. C₆H₁₂O₆ contains carbon atoms, hydrogen atoms, and oxygen atoms.
4. How many atoms of each element are in 2H₂SO₄?
Hydrogen:
Sulfur:
Oxygen:
5. Determine the number of atoms for each element in 3Ca(OH)₂.
Calcium:
Oxygen:
Hydrogen:
6. How many total atoms are present in the chemical formula Al₂(SO₄)₃?
8
14
17
20
7. In the formula Mg₃(PO₄)₂, there are 8 oxygen atoms.
True
False
8. A compound has the formula (NH₄)₃PO₄. How many atoms of each element are present?
Nitrogen:
Hydrogen:
Phosphorus:
Oxygen:
9. Explain the difference between a subscript and a coefficient in a chemical formula, and how each affects the atom count.