Have you ever stopped to think about how we have so many different natural and man-made materials? From metal to leather and concrete to wood, how do all these variations actually exist? Put simply, it's the result of different types of atomic bonds. These bonded atoms stem from the wave nature of electrons. All of this works to formulate the material things in our everyday lives.
We are surrounded by different types of natural and human-made materials at every point of our daily lives, and these materials result from different types of atoms combining, bonding, in different ways.
But, have you wondered why atoms form bonds in the first place?
In organic chemistry, the most common, and essential, form of chemical bonding is covalent bonds. Covalent bonds form when electrons are shared between atoms to create a molecule. This means that electrons that were in their respective atomic orbitals come together, and a new molecular orbital is formed that includes both atoms and the shared set of electrons.
When atoms bond to become a molecule and a new molecular orbital is created, the overall energy of the electrons goes DOWN compared to when the electrons were simply in their atomic orbitals. Lowering of electron energy means an increase in stability, so atoms want to be in bonds because by doing so, they become more stable. This is why atoms generally never exist on their own and instead combine with other atoms to form molecules and other structural forms of matter.
To better understand why the energy of the electrons goes down in a molecular orbital, we have to discuss the wave nature of electrons.
Electrons, like sound and light, have a wave nature, and this means that we can describe the atomic and molecular orbitals in context of their wavefunctions. Molecular orbitals are created when the wavefunctions of the individual atomic orbitals get close enough to overlap in space. This results in two diverging scenarios where the two wave functions add together to create a larger bonding molecular orbital, OR where the two wavefunctions cancel each other to create an anti-bonding molecular orbital that we will discuss at a later time.
Because bonding molecular orbitals are larger than atomic orbitals, this means that the wavelengths for the electrons are now longer. When the wavelength becomes longer, this results in lower momentum that in turn lowers the kinetic energy. This lowering of energy is what ultimately drives covalent bonds to form, giving us the physical materials that surround us.
…and it is all a consequence of the wave nature of electrons.
