•In the old days compounds had common names like: water, milk of magnesia, gypsum, quicklime, etc.
•Today we know of over 4 million compounds. Common
names won’t work
•Therefore we have a system!
•First we will learn about
binary compounds, compounds made of two elements
•There are two classes: 
• 1) metal/nonmetal
• 2) nonmetal/nonmetal