Worksheet titled "Counting Atoms" designed to teach students how to determine the number of atoms in various chemical compounds.

1. a) The element symbol which are represented by a single uppercase letter, or represented by an uppercase letter followed by a lowercase letter. This tells you the types of elements in the compound.
b) The subscript which are numbers that are found on the lower right-hand side of each element symbol. This tells you the number of atoms of this element in the molecule. If an element symbol has no subscript next to it, then this indicates that there is only one atom of this element in the molecule.
c) The parentheses which surround some groups of atoms indicate that the numbers of all of the atoms inside the bracket need to be multiplied by the number on the outside of the bracket found on the lower right-hand side of that bracket.

2.
1) NaOH
- Na: 1
- O: 1
- H: 1
- Total: 3

2) HNO₃
- H: 1
- N: 1
- O: 3
- Total: 5

3) Li₂O
- Li: 2
- O: 1
- Total: 3

4) Li₂SO₄
- Li: 2
- S: 1
- O: 4
- Total: 7

5) NH₄Cl
- N: 1
- H: 4
- Cl: 1
- Total: 6

6) Ca(ClO)₃
- Ca: 1
- Cl: 3
- O: 3
- Total: 7

7) H₂COCH₂
- H: 4
- C: 2
- O: 1
- Total: 7

8) Mg(OH)₂
- Mg: 1
- O: 2
- H: 2
- Total: 5

9) Al(OH)₃
- Al: 1
- O: 3
- H: 3
- Total: 7

10) NH₄C₂H₃O₂
- N: 1
- H: 7
- C: 2
- O: 2
- Total: 12

11) NaC₂H₃O₂
- Na: 1
- C: 2
- H: 3
- O: 2
- Total: 8

12) (NH₄)₃PO₄
- N: 3
- H: 12
- P: 1
- O: 4
- Total: 20

13) Ca₃(PO₄)₂
- Ca: 3
- P: 2
- O: 8
- Total: 13

14) Fe₂(CO₃)₃
- Fe: 2
- C: 3
- O: 9
- Total: 14

15) Al₂(SO₃)₃
- Al: 2
- S: 3
- O: 9
- Total: 14