Covalent, Metallic or Ionic Bonds

A chemical bond is the "glue" that holds atoms together. Chemical bonds can be weak or strong, and everything in between! 

One thing that all chemical bonds share is that they are just an atom's attempt to complete its outer shell of electrons, or valence electrons. The closer an atom's valence shell comes to being completely full, then the closer that atom comes to resemble an inert, or noble, gas.

It turns out that all atoms strive to have the electronic configuration of an inert gas atom! Why is that such a desirable state? Inert gases are extremely stable. In fact, inert gases are so stable that they don't bond, ever, to anything. They are perfectly content to remain just as they are.