Thursday, November 13, 2008

"BBA" is for...

Bad Bond Angle!

There are a few things I insist on in Organic Chemistry. One of the big ones is that I expect students to draw realistic bond angles. I am always reminded that this must be very hard for students to do. Even my best students draw impossible bond angles.

Things look like this:

These present teachable moments. I don't bring the sledgehammer down. Just a calm and stern correction. What they have drawn is wrong, and they can learn from their mistakes with proper guidance.

Eventually, when they should know better, I take points away. I once had a student ask me why I took points away. I told her it was because her answer was wrong. She didn't like that. Apparently she felt her ability to put something onto paper was worthy of credit. I had to convince her otherwise.

7 comments:

the iNDefatigable mjenks said...

They probably frown on rulers across the knuckles these days, don't they?

Chemgeek said...

The frowning upon all types of physical discipline have forced us teachers to utilize psychological means of abuse.

Worse, since the Vulcan Mind Meld involves touching the student (which is not allowed) I have had to resort to using the Force. However, I never completed Padawan school so I find this technique very difficult.

Russ said...

Another one that fits into your list of classic student errors would be drawing a wedge and dash bond from the same atom at 180 degrees from each other. That one always seems to come up in the early tests on stereochmistry.

Chemgeek said...

Russ, oddly enough, I just correct some homework that had that error on it.

They'll figure it out eventually.

milkshake said...

As the buttler ghost Delbert Grady says: "Perhaps they need a good talking to, if you don't mind my saying so. Perhaps a bit more. My girls, they didn't care for the Overlook at first. But I corrected them. And when my wife tried to prevent me from doing my duty, I corrected her.

Ψ*Ψ said...

My boss (the acetylene fetishist) would throw a fit over the second one!

Lisa-tastrophies said...

Chemgeek: I have tried the Force. Doesn't work on Jr. High kids. You might have more luck on college students. You're right about them wanting credit just for putting something on a piece of paper. WOW. What ever happened to "earning" a grade? My students and occasionally a parent will tell me I "GAVE" him/her child a grade. Really? Because based on the amount of effort that went into the work, I would still only GIVE them an "F"

P.s. I SO wish I had paid more attention in chemistry so I could understand more of what you are talking about sometimes ;-)