**[Download the accompanying PDF worksheet.]**

**Perform the following calculations, being sure to give the answer with the correct number of significant digits.**

- How many atoms are in 8.21 g Li?
- What is the mass in grams of 4.17×10
^{21}formula units of magnesium perchlorate? - How many sulfur atoms are in 72 g of cobalt(III) sulfate?
- How many grams of lithium are in 30.6 g of lithium nitride?
- A sample of cadmium borate contains 72.9 g of boron. What mass of cadmium will the sample contain?
- What is the mass of sulfur in grams in a sample of manganese(VI) sulfate containing 8.291×10
^{24}oxygen atoms?