Chapter 3 Chem 131-7-23 (Last saved by used) Microsoft Word non commercial use 2 1. Definition. What is the molar mass of an atom? What are the commonly used units for molar mass? 2. How many grams of gold (Au) are there in 15.3 moles of Au? 3. What is the mass in grams of a single atom of each of the following elements? a. As b. Ni 4. A modern pennyweights 2.5 g but contains only 0.063 g copper (Cu). How many Cu atoms are present in a modern penny? 5. Which of the following has more atoms: 1.10g of hydrogen atoms or 14.7g of chromium atoms