Formation of binary ionic compounds Binary ionic compounds are often more stable than the elements from which they are formed, because their formation is likely to be exothermic or very exothermic. When a binary ionic compound forms, energy is needed to remove electrons from atoms of the metallic element, and to break bonds (metallic bonds in a metal and covalent bonds in the non metal). Energy is released when electrons are added to atoms of the non metal and, more importantly, when the ions come together to form the crystal lattice. The energy that is released if far greater than the amount of energy that is used. 
