So, definitionally speaking, what is Chemistry? Simply put, Chemistry is the scientific study of matter. Matter, of course, is made of substances, and substances can be broken down into elements, which are pure, unmixed stuff that make up everything we find in the universe, including ourselves. 

In the mid-1800s, a scientist called Dimitri Mendeleev invented the Periodic table, wherein he organized all of the known elements based on their masses and characteristics.

Every element on the periodic table has an Atomic Mass number, which is how much an average single atom of a specific substance weighs in Atomic Mass Units (amu). 

Atoms are made of three known “parts”, for lack of better terms: protons, neutrons, and electrons. Only protons and neutrons make up the center of an atom- known as the nucleus- while electrons are only found orbiting around the nucleus of an atom.

Atomic Mass essentially refers to the average mass of the protons and neutrons combined in a single atom’s nucleus. Electrons weigh so little that they really don’t impact an atom’s Atomic Mass, and are thus not included in an atom’s overall mass (at least, not in basic college Chemistry). 

Interestingly, atoms of the same general element can have different numbers of neutrons and electrons. For instance, a regular (AKA uncharged) Carbon atom has 6 protons and 6 neutrons. When you add those two numbers together, you get Carbon-12. However, Carbon-13 and Carbon-14 also exist. 

Carbon-13 is what happens when a Carbon atom has 6 protons and 7 neutrons. Carbon-14 has 6 protons and 8 neutrons. Again, electrons are so small that they are not included in these calculations. 

However, electrons become important when determining whether or not an atom is neutral, positively-charged, or negatively-charged. Something, something, ionic vs covalent compounds… 

To be continued…