Ionic Compounds

The process of ionic bonding is one that is fundamentally important to our known universe, and it is a vital part of everyday life.  Ionic bonds are a special type of bond that bonds two atoms together.  These atoms must be a metal and a non-metal, and they must be in very specific chemical families to form ionic compounds.  

The way an ionic bond is formed is based solely on the number of valence electrons each atom has.  The octet rule says that for an atom to be as stable as possible, it must have eight electrons in the outer (or valence) electron level.  Notice that all metals have 4 or fewer electrons in this level, and that all nonmetals have 5 or more valence electrons.  Thus, the only way an ionic compound can be formed is if the sum of each atom’s respective valence electrons is equal to eight.  Thus an element from the alkali metals (with one valence electron) will be able to form an ionic compound with a halogen (which each have seven valence electrons).  Obviously Noble gasses do not form ionic compounds, because they already have a full octet of electrons in the outer level.   

One of the most common and plentiful ionic compounds is sodium chloride, which is written in chemical notation as NaCl.  This, believe it or not, is ordinary table salt, used for a plethora of purposes such as baking, seasoning food, and preserving meat before the discovery of modern refrigeration technologies.   

Another common ionic compound is the weapon of many super-villains, hydrochloric acid.  This is simply the aqueous (dissolved in water) form of the ionic compound hydrogen chloride.  HCl is a very strong acid, capable of massive corrosion when present in high concentration.  However, it is most commonly present in high school chemistry labs to showcase neutralization with a base or to provide excess hydrogen ions to aid a redox reaction.  

Calcium carbonate is an ionic compound which is used mostly in the classroom.  CaCO3 is actually more commonly known as chalk, and is used in great quantities in schools across the globe in every subject area imaginable.  Unfortunately, use of this ionic compound is decreasing rapidly, due to the more air-friendly whiteboards and SMARTboards that are available.  

These are just a few examples of ionic compounds of the hundreds possible found in nature.  It is one of the most important tasks of chemists to identify these compounds and use their properties to enhance contemporary society.  Better living through chemistry is not just an adage, it is indisputable fact.