Why I Teach Chemistry Before Biology
Students, like all of us, learn best when they’re learning usable information. For all students, that means showing students how chemistry, biology, and physics not only explain everyday things, but also more complex phenomena they’re likely to encounter in pursuing their future careers.
As for which science to teach first, it seems senseless to me to teach biology before chemistry when so much of biology is chemistry of the cell. Apparently, the reason for delaying chemistry until after biology is because of all the math needed in chemistry. In fact, though, the math needed in chemistry is not particularly difficult, certainly not difficult enough to justify teaching such complex biological subjects as how cells capture energy from sunlight, how cells generate energy, how cells synthesize proteins, how cells communicate with other cells, the structure of DNA and RNA and how cells reproduce DNA and RNA during cell division, and the list goes on.
The fear of chemistry is unjustified. Chemistry is pretty straightforward because it stems from the following central core of knowledge that takes just a couple of weeks to understand.
There are about 100 different atoms in the world, all listed in the periodic table, and all with the same basic structure of a “nucleus” made of positively-charged “protons” surrounded by clouds of negatively-charged “electrons.” The smallest atom is hydrogen with a single proton in its nucleus and a single electron around the nucleus. Each time a proton is added to the nucleus, and with it, an electron around the nucleus, a new atom is created, and listed as an “element” in the periodic table.
When 2 atoms bond to each other, they form a molecule. What makes chemistry so straightforward is that atoms bond to each other in only 1 of 4 ways. Each method of bonding creates a molecule with characteristic properties, like its melting point and boiling point, whether it dissolves in water, floats or sinks, whether it’s shiny or dull, smooth or rough, soft or hard, dense or fluffy, and whether it’s a gas, liquid, or solid at room temperature, and so on.
Chemistry, then, is introducing students to the 100+ atoms in the world, showing them the 4 ways atoms bond to each other to form molecules, and explaining why each of the 4 ways of bonding produces molecules with characteristic properties. The rest of chemistry is measuring the number of atoms and molecules, their weight, ways to make atoms more likely to bond to each other, and ways to modify their properties.
It only takes a few weeks to teach students the 4 ways atoms bond to each other. If you have any doubt, I invite you to view my 1-hour video explaining the 4 ways atoms bond, called “Chemistry in an Hour,” visible here on this website.
Once students understand the 4 bonds, the rest of chemistry is explaining how the 4 bonds can be modified to change the properties of molecules, and how we measure the number and weight of molecules, their pressure, how they form acids and bases, and how the four methods of bonding can be modified to create molecules with unique properties.
The point I’m trying to make is that understanding the how the 4 ways atoms bond to form molecules with characteristic properties makes biology so much more understandable. Students will have a much better understanding of how plants and animals absorb energy, how they reproduce, adapt to their environment, compete for energy, and evolve. They’ll understand why natural and man-made things are waterproof, why gasoline is such an effective and efficient source of energy, why plastics are both good and bad, why air pollution is so detrimental to us and to the environment.
Moreover, learning chemistry before biology gives students a different outlook on our environment. They’ll appreciate, for example, why we have so much trouble breaking the chemical bonds in all the biological and man-made products we use and consume, and that are now accumulating into mountains of garbage and polluting our rivers, lakes, and oceans.
Chemistry is not only the basis for biology, it’s also the basis for physics, because physics is the study of forces – the forces of motion, magnetism, electricity, electromagnetic forces, and nuclear energy. Every one of these forces is found in every atom. Mechanical forces, for example, stem from the movement of atoms. Electrical forces stem from the negative electrical charges on electrons and positive electrical charges on protons. Magnetic forces are created by spinning electrons, and electromagnetic forces form when electrons jump from 1 orbit around a nucleus to a higher or lower orbit.
In short, I think teaching chemistry after biology only frustrates and sours budding careers in science by expecting young minds to understand and appreciate biology without understanding the chemical structure of biology.