Introduction to Organic Chemistry

A lot of people think chemistry is a complex, hard to learn subject. And while there is a lot to the field, I wanted to show that the underlying foundation of it all is actually pretty easy. It follows well defined rules and then builds on those rules in fascinating ways.

There are more than a hundred chemical elements, each one with its own properties. But not to worry, because for organic chemistry we only have to concern ourselves with a handful of elements. Best of all, the elements have helpfully arranged themselves into groups of similar properties, which we represent with the periodic table.

When different elements combine together in a given ratio, they form a compound. Every atom belongs to one of the elements; it is an indivisible (under ordinary conditions) smallest possible piece of that element. When two or more atoms join together, they form a molecule. A compound is a substance made up of multiple identical molecules. Atoms and molecules are very tiny; an ounce (28.5 grams) of water consists of almost nine hundred and fifty thousand million million million molecules. The distances between atoms that are bonded together are mostly in the vicinity of 1 to 2 Angstroms. There's 10 Angstroms in a nanometer, a thousand nanometers in a micron, a thousand microns in a millimeter, and a thousand millimeters in a meter.

For now, let's start with an atom of carbon, or element number 6. We can write it as a capital letter C. Or we can depict it as a ball. The usual color for carbon is black:

Carbon has four bonds. We can think of it like carbon has four sites where it attaches to other atoms. We say 4 is carbon's valence. A carbon atom is almost never found alone; it tends to always be bonded to something.

Hydrogen can be written with a capital H. Hydrogen only has one bond; its valence is 1. Its usual color is white or bluish white:

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