When elements combine to make compounds, they form strong chemical bonds to each other so that the compounds now behaves as a single new substance. In this chapter, we will see that there are two ways that atoms bond to each other: either by transferring electrons or by sharing them. These two types of bonding are called ionic and covalent. We will learn to draw Lewis structure for atoms and molecules and see how we can use these to show (and predict) bonding patterns in compounds. Finally, we will learn how to systematically name and classify compounds using simple rules based on the type of bonds used to construct them.