What’s the difference between ionic and covalent bonds by ZME Science Every bit of matter around you is held together by chemical bonds. Sometimes, chemical bonds are broken, such as during a chemical reaction, only for atoms to bond again to form different molecules. Energy is always released to generate bonds and, likewise, energy is always required to break bonds.There are two main types of chemical bonds: ionic and covalent. What are ionic and covalent bonds? Atoms bond together to form compounds because in doing so they attain lower energies than they possess as individual atoms, becoming more stable in the process. By the Law of Conservation of Energy, when a new chemical bond is formed, the chemical reaction releases an amount of energy (usually as heat) almost equal to the difference in the amounts of stored chemical energy between the products and the reactants. This stored chemical energy of the system, or heat content, is known as its enthalpy. An ionic bond form...