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Counting Atoms in Compounds

A Grade 7 science worksheet focused on understanding how to count atoms in chemical compounds using chemical formulas.

Grade 7 Science ChemistryCounting Atoms in Compounds
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Includes

Fill in the BlanksMultiple ChoiceShort AnswerTrue / False

Standards

MS-PS1-1

Topics

chemistryatomscompoundsmoleculesformulasgrade7
6 sections · Free to use · Printable
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Counting Atoms in Compounds

Name:

Date:

Score:

Read each question carefully and answer to the best of your ability. Show your work for counting atoms where indicated.

1. A chemical   shows the elements in a compound and the ratio of atoms.

2. The small number written after an element symbol is called a  .

3. If there is no subscript after an element symbol, it means there is only   atom of that element.

4. How many oxygen atoms are in the chemical formula H₂O?

a

1

b

2

c

3

d

0

For each chemical formula, identify the elements present and count the number of atoms for each element, then state the total number of atoms.

5. CO₂

Elements and atoms:

Total atoms:

6. NaCl

Elements and atoms:

Total atoms:

7. C₆H₁₂O₆ (Glucose)

Elements and atoms:

Total atoms:

8. The chemical formula for water, H₂O, indicates there are two hydrogen atoms and one oxygen atom.

T

True

F

False