too much information
Nov 17th 2005Wallabynerd alert
One of the hardest things for professors to do in teaching is to explain things in ways that people actually understand. This isn’t exactly news, but it was brought to mind again last night by the freshman I was tutoring.
He was having trouble with the idea of a dipole moment — which is just a fancy way of saying that a molecule (or ion) has more electron density on one end/side than on the other, so it’s got a little bit more positive on one end than on the other. “Ohhhh!” he said, his eyes going wide. “That’s all? My professor just kept saying that ‘a molecule has a dipole moment if there is no center of inversion or Cn symmetry’….” “Yeah, well, that’s true, but it doesn’t exactly help, does it.”
Tuition and fees at a major public university: $10,000
Hours spent in class listening to a physical chemist get confused about which class he’s teaching: 30
Hire a grad student to use English: $20
Finally understanding hybrid orbitals…. priceless.
2 Responses to “too much information”
*I* liked the “no Cn symmetry”: a transparent explanation. But people do see things in different ways, Bill Gates to the contrary. And finally getting it is precious. The trick is to click to what it takes to get the essence accross, together with application to make it stick.
The problem is that symmetry isn’t taught in general chemistry; it’s generally not done until physical or inorganic chemistry (probably whichever one is “expected” to be taken first in that particular department). So, for freshmen non-majors who’ve never had any exposure to the terms, it’s a complete “explanation” in a foreign language, Hearing an unfamiliar term in class *should* prompt the student to go look up the new term, which isn’t difficult these days. Then again, it doesn’t cost the professor more than a minute or two to provide both explanations and get through to a much larger fraction of the class.