Answer: Breaking covalent bonds in molecules results in the dissipating the energy of atoms held together in molecules.
Explanation: By way of introduction,
Covalent bonds are one of four types of chemical bonds. The other three are ionic bonds, metallic bonds and hydrogen bonds. Each bond type differs in the way atom share electrons. In covalent bonds, two atoms completely share one or more pairs of electrons. These bonds are quite strong.
Covalent bonds form between atoms when the total energy present in the newly formed molecule is lower than the energy present in each of the atoms alone. The lower energy when bonded results from the fact that atoms are more stable when their outer electron shells are full. Atoms can fill their outer shells by sharing electrons with other atoms though the formation of covalent bonds.
It is important to know that there is a symmetrical relationship between the amount of energy released during the formation of a covalent bond, the amount of energy needed to break the bond. Breaking covalent bonds requires energy, and covalent bond formation releases energy.
This energy is measured as heat using the units joules or calories or kilocalories.
The amount of energy released during molecule formation can be estimated by counting the number and types of bond in a molecule. For instances, a methane molecule has one carbon atom bound to four hydrogen atoms via four single carbon-hydrogen covalent bonds. Carbon-hydrogen bonds release 100 kcal/mole of energy when formed, so the total energy needed to break all the bonds in a methane molecule is 100 kcal x 4 or 400 kcal.
