Part 2: Fundamental Chemistry—Periodic Table

Over time, scientists have developed a way to organize the elements based on their unique characteristics. All of the elements have been arranged into a useful, standardized document called the Periodic Table. This table groups atoms by the number of protons in its nucleus and by chemical and physical characteristics using a series of columns and rows. Columns run vertically and are referred to as “groups,” while rows run horizontally and are referred to as “periods.” When using the Periodic Table, there are some important numbers and symbols to be aware of:

1. Symbol: To simplify the process of drawing molecules and writing chemical equations, each atom has been given a characteristic symbol. For example, the symbol for carbon is “C” and the symbol for iron is “Fe.”
2. Atomic Number: Also referred to as the “proton number, ” the atomic number is determined by the number of protons in an atom’s nucleus. As you move across the rows of the Periodic Table, you can see that each successive element increases by one proton (and one electron). Because each atom has a different number of protons, this number is important for classifying and distinguishing atoms.
3. Molecular Mass: The molecular mass is determined by the mass of the protons and neutrons in an atom’s nucleus (electrons are not included in this number because they are so tiny that their mass is considered negligible in comparison with larger protons and neutrons). The more subatomic particles an atom has, the heavier it will be. For convenience, this number is included on most periodic tables.

All of the elements found in essential oils can be found on the periodic table. In fact, most essential oils are complex combinations of carbon, hydrogen, and oxygen, though some constituents may also contain nitrogen or sulfur.