We have come a long way understanding the nature of electrons, which play the most important part in any type of bonding. From now on, we will focus on the structure of covalent bonding. If you need to review any previous material on the nature of electrons, feel free to do so by clicking on 'Previous Section' above this page.

What is a covalent bond? If you remember from the very first page, it is simply a bond that results from the attraction between elements sharing electrons. Basically, the two elements are sharing electrons together. Lets look at the simplest case of covalent bonding - the hydrogen molecule.

If you recognize the first figure, you know that you are looking at two s-orbitals, which is simply two hydrogen atoms. When the two hydrogen atoms come close enough to each other, the overall energy begins to drop. Remember, nature loves lowest energy states and will go in that direction to achieve lower energy. Thus, the hydrogen atoms will keep pulling themselves closer and closer. Soon, the s orbitals begin to overlap to a point where energy is the lowest. A covalent bond has formed at this stage and the result is a molecule. Look at the following diagram. It represents the energy diagram of hydrogen as their atomic distances between their nuclei decrease. Note what happens when the nuclei continue to pull themselves close even more: the energy starts to increase rapidly since the nuclei try to repel each other.

What happens to the electron configuration of the hydrogen atoms after they are bonded? Look at the following diagram. Because they are sharing their electrons, the electron configuration becomes similar to that of helium. An important note: when atoms bond, they are trying to achieve an octet, or an electron configuration where all orbitals are filled up. Such an octet is present in the noble gases, such as helium, neon, argon, krypton, xenon, and radon. Thus, the hydrogen molecule has achieved an electron configuration similar to helium and is "satisfied" there.

In the next section, we will look at bonding between other different elements. Click on 'Next Section' to continue.