Atomic structure and ignorance...

While Foxy catches up on all the stuff that accumulated during her involuntary time off she is providing me an opportunity to bore you further with some of my thoughts.

On Monday I will have the pleasure of describing to a class of non-science majors the structure of atoms. This isn’t as easy as it sounds. Chemistry possesses a definiteness that leaves little room for interpretation. The structure of atoms is not like the influence of western culture on the indigenous people of Central America. You can’t finesse an answer on an exam and hope for partial credit. We’ve all done that and you know it. I recall writing an analysis of a story I never read based solely on the title and getting a passing grade. Perhaps I can best explain the difference by saying that most subjects are qualitative with concepts explainable in general terms whereas chemistry is quantitative. Chemical concepts are based on physical laws represented by mathematical expressions. That’s probably why so many people avoid chemistry.

The conventional approach taken by textbook authors involves a long and tedious historical perspective that presents several different atomic models all of which have been discarded. My favorite explanation is the one where Lord Kelvin describes the atom as being like a plum pudding. What 18 to 20 year old students can relate to plum pudding? Should the author modernize the statement and say the atom is like chocolate chip ice cream? I say, what’s the point? The model is completely wrong and belongs in a history of science course.

Forty years ago everything in this course would have been taught in high school chemistry and back then one had to pass chemistry in order to gain entry into college. Now it seems you can avoid all of the sciences and even limit yourself to a single year of algebra in high school without seriously handicapping yourself. If you can afford the tuition you have met all the requirements.

Even wearing my rose color glasses won’t erase the fact that today’s high school graduates are totally unprepared for what should be college level work. I believe the expression is 'dumbing down.' And don’t think this is limited to math and science. The average college freshman is so ignorant it borders on astounding.

I ask my students to fill out a questionaire during our first meeting, mostly to get some idea of what math and science they have taken before, but I throw in a couple of unrelated questions just for fun. For example I learned that out of about 30 students only one knew that Colorado was directly north of New Mexico. I find this difficult to fathom since I can draw from memory a reasonably accurate map of the United States naming every state and even naming most of the capitols correctly. Times have changed.

Now imagine these clueless students filing into Ward Churchill’s class and listening to him spout an endless stream of anti-American propaganda for fifty minutes or so every day. Can you visualize their 'deer in the headlights' stare while they think to themselves, “I didn’t know that”? Soon a semi-cohesive thought is generated by a few misfiring brain cells and they begin to accept what he says without question and become miniature walking Ward Churchills spreading his hatred and joining the ranks of those who Vladimir Lenin called the useful idiots.

I leave my politics outside of the classroom. I like to think most professors in the sciences do the same. I wish I could say the same for other disciplines. But if you look at the names of some of the available courses you see that many of them have been created for the express purpose of advancing a particular ideology. Go to some university websites and look at what is offered and then decide for yourself what ideology I am talking about. I’m not going to tell you.

But I digress. I’m still no further along figuring out how I’m going to present atomic structure. I would like to assume that students already know that matter is made up of tiny invisible particles called atoms but I can’t. Nor can I assume that almost everyone knows that opposite charges attract one another and like charges repel one another.

So where do I start. I suppose I could practice my lecture on my dog and see how he responds. I know he will give me about the same feedback I usually get from my class. Well, actually more since he will wag his tail and probably try to lick whatever exposed skin is available at that moment. None of my students have ever licked my kneecaps.

Seriously though, my current students are a pretty good bunch and even attend classes. I interpret that as a good sign. Sleeping in class is a common problem especially during evening classes but hasn’t been a problem this semester except once. But it wasn’t serious because one of the students woke me up. Gotcha again.

In order to properly discuss the structure of an atom one must understand the nature of light or as we scientists say, electromagnetic radiation. Light presents a dual nature (sort of like a tiny invisible politician). The light behaved like a wave before it behaved like a particle. We also talk about concepts such as wavelength, frequency, energy, refraction, diffraction, and the photoelectric effect. If you don’t know what I’m talking about don’t feel bad; my students don’t either.

This course requires that I teach about atomic orbitals. In a way this part of the course looks like a sort of quantum mechanics lite. So I merrily explain how s-orbitals are spherical and p-orbitals have lobes. And all of this is easily explained through the use of a few quantum numbers. Naturally if you have your periodic table you will always know if you are dealing with s-orbitals or p-orbitals. You got that? Good, because s and p orbitals form hydrids which have the character of both. And that’s why so many molecules are tetrahedral, except February which has 28 days. Wow, it’s a lucky thing that the electons in any given suborbital have opposite spins.

By now you are all wishing you were taking my class. I promise you will probably not have to learn about wavefunctions.