Home / Worksheets / Grade 12 / Science / Counting Atoms in Compounds

Counting Atoms in Compounds

This worksheet focuses on understanding chemical formulas and accurately counting the number of atoms for each element within various chemical compounds, suitable for Grade 12 chemistry students.

Grade 12 Science ChemistryCounting Atoms in Compounds
Use This Worksheet

Includes

Fill in the BlanksMultiple ChoiceShort AnswerTrue / FalseMatching

Standards

HS-PS1-1HS-PS1-7

Topics

chemistryatomscompoundsstoichiometrychemical formulas
7 sections · Free to use · Printable
← More Science worksheets for Grade 12

Counting Atoms in Compounds

Name:

Date:

Score:

Carefully read each chemical formula and determine the total number of atoms for each element present in the compound. Pay close attention to subscripts and coefficients.

1. In the compound H2O, there are   hydrogen atoms and   oxygen atoms.

2. The formula for glucose is C6H12O6. This compound contains   carbon atoms,   hydrogen atoms, and   oxygen atoms.

3. For the compound 2NaCl, there are   sodium atoms and   chlorine atoms.

4. In Ca(NO3)2, the number of calcium atoms is  , nitrogen atoms is  , and oxygen atoms is  .

5. How many total atoms are in one molecule of sulfuric acid, H2SO4?

a

6

b

7

c

8

d

9

6. Which of the following compounds contains the most oxygen atoms per molecule?

a

CO2

b

H2O2

c

N2O5

d

SO3

7. Determine the number of each type of atom in 3 molecules of (NH4)3PO4.

8. A chemist needs to prepare a solution containing 10 moles of water. How many hydrogen atoms are present in this amount of water?

9. In the chemical formula 5Al2(SO4)3, there are a total of 10 aluminum atoms.

T

True

F

False

Match the compound with the correct number of oxygen atoms.

10. C12H22O11

 

a. 2

11. KMnO4

 

b. 4

12. H2CO3

 

c. 3

13. NaHCO3

 

d. 11