Name: _____________________________________ Date: ______________
Mr. Sullivan
7th Grade Science
Atoms vs. Molecules: Chemical Formulas
Directions: First, count how many atoms are shown in each chemical formula.
Then, determine if the chemical formulas show atoms or molecules.
Number of Atoms Shown in Each Formula
CO
H2 O
Rn
Co
He
W
C12H22O11
CO2
Ag
O
O2
O3
HCl
Atom
Molecule
Atoms vs. Molecules and Elements vs. Compounds Summary Questions
Directions: Use the atom/molecule and element/compound and tables from class to
answer the following questions.
1. How do you know that Rn is a chemical formula for an atom?
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2. How do you know that Rn is a chemical formula for an element?
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3. How do you know that C12H22O11 is a chemical formula for a molecule?
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4. How do you know that C12H22O11 is a chemical formula for a compound?
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5. How do you know that O3 is a chemical formula for a molecule?
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6. How do you know that O, O2, and O3 are all chemical formulas for an element?
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