You will need a calculator for this exercise.

1. In order to go from number of moles to number of atoms or molecules:

   1.   ?    divide by 6.02 x 10²³.
   2.   ?    multiply by 6.02 x 10²³.

2. To go from number of atoms or molecules to number of moles:

   1.   ?    multiply by 6.02 x 10²³.
   2.   ?    divide by 6.02 x 10²³.

3. If I had 6.02 x 10 ²³ atoms of Oxygen, how many moles would I have?

   1.   ?    3
   2.   ?    2
   3.   ?    4
   4.   ?    1

4. If I had 3 moles of Carbon, how many atoms would I have?

   1.   ?    12.06 x 10 ²³ atoms
   2.   ?    18.06 x 10 ²³ atoms
   3.   ?    6.02 x 10 ²³ atoms
   4.   ?    24.08 x 10 ²³ atoms

5. If I had 2.5 moles of Lithium, how many atoms would I have?

   1.   ?    12.04 x 10 ²³ atoms
   2.   ?    6.02 x 10 ²³ atoms
   3.   ?    15.05 x 10 ²³ atoms
   4.   ?    17.25 x 10 ²³ atoms

6. If I had 12.04 x 10 ²³ atoms of Magnesium, how many moles do I have?

   1.   ?    2.5
   2.   ?    3.4
   3.   ?    4
   4.   ?    1
   5.   ?    3
   6.   ?    2

7. If I have 2.1 x 10 ²⁴ atoms, how many moles do I have?

   1.   ?    4.5
   2.   ?    2
   3.   ?    3
   4.   ?    3.5
   5.   ?    4
   6.   ?    1
   7.   ?    2.5
   8.   ?    1.5

8. How many atoms are in 3.4 moles of Potassium?

   1.   ?    2.05 x 10²⁴ atoms
   2.   ?    1.2 x 10²⁴ atoms
   3.   ?    5.6 x 10²² atoms
   4.   ?    1.32 x 10²⁴ atoms

9. How many moles are in 2.53 x 10²⁴ molecules of Silicon?

   1.   ?    5.2 moles
   2.   ?    4.2 moles
   3.   ?    1.53 moles
   4.   ?    1.9 moles

10. How many molecules are in 7.5 moles of CO₂?

    1.   ?    1.35 x 10²³ molecules
    2.   ?    8.02 x 10²⁴ molecules
    3.   ?    330 molecules
    4.   ?    4.5 x 10²⁴ molecules