Atoms are the basic building blocks of all matter. Each atom contains a nucleus (the center), which is composed of protons and neutrons, and an outer electron cloud, where the electrons dwell.
|I'm going to use computer-drawn figures after this post, but for my purposes here, I thought my hand-drawn figures would be a little less sterile.|
Elements (remember the periodic table?) are defined by their number of protons; that is, a hydrogen atom has 1 proton, a helium atom has 2, lithium has 3, and so on.
|Example of entries in a periodic table; these are the element abbreviations: H = hydrogen, He = helium, Li = lithium. We're all about abbreviations!|
To form molecules, atoms need to get together and bond; this is through the sharing or exchanging of electrons. Electrons are important, people! A single bond consists of two electrons; you can also have double bonds and triple bonds, which each add on another two electrons.
Chemical reactions are due to bonds breaking or forming. To illustrate this, we use pictures and arrows.
Molecules are written out (e.g. H2O, water) or drawn out. The picture gives us more information.
|One of my favorite molecules :)|
However, drawing out all of those carbons and hydrogens gets time consuming, so we have a shorthand. Any non-carbon/hydrogen atom is still written in.
|You can count all the points and assure yourself that all of the carbons and hydrogens are still accurately represented.|
Okay. Take a deep breath. Still with me? This is easy, right? There are no tests. This is only for your personal information! Now that we have all of that done, I'm going to throw out a couple of things to think about.
|More examples of familiar molecules, drawn out in shorthand.|
First, the word "chemical" encompasses all things. Water is a chemical; its formula is H2O and it has many systematic chemical names, such as dihydrogen monoxide. Say it out loud. Sounds scary, doesn't it? It's still water. So when companies claim to be "chemical-free," you can see why I'm a little skeptical. There are substances I want to avoid, for a variety of reasons, but in that case I really prefer it when they list exactly what they are eliminating, e.g., "free of X, X, X, X."
Second, there's really no hard and fast rule for what makes something a "bad" chemical, and what makes it a "good" one. There are classes of compounds that are toxic to humans, of course, but sometimes a small change (substitution of a single atom, for example) can make a big difference. For example, look: here are methanol, and ethanol. As their names imply, they are very similar in structure - ethanol has one more carbon and a few more hydrogens. However, methanol in all forms is poisonous; ethanol is diluted and consumed for pleasure (vodka, rum, gin, wine, etc.).
All right, I'm done. Class dismissed! Seriously, though, I really want to make science less intimidating. If this was not helpful at all, please let me know - I want to make it easy to follow and as clear as possible. I would love to hear from you, whether it's because you hated it, you loved it, you're looking forward to more, whatever it is. Also, if you have questions or need a little more, please feel free to email me or leave a comment below. The next topic I'll be covering is antioxidants and free radicals, which I'm excited about. I'm still taking suggestions for other topics!
Also, I feel that there are many ways to teach and learn. For more information about drawing structures and basic organic chemistry, check out this.