Hi! When chemical reactions take place, elements bind to each other to form entirely different compounds. There are a number of different types of covalent bonding, such as ionic, metallic and compound bonding, all of which usually involve the transfer of electrons. A summary of each is: 1. Ionic bonding - the exchange of electrons between a metal and a nonmetal 2. Metallic bonding - bonding between two or more metal ions 3. Covalent bonding - bonding between two non metals hope that helps!