Sunday, November 30, 2008

A Little Lesson on Surface Tension


My first year of teaching high school chemistry was interesting to say the least. Kids do say the darndest things, but when it's 17 year olds it puts a whole new spin on things. They understand what words mean but sometimes they still don't understand what two words mean when put together.


By the second semester of the school year, I think that teachers have established a pretty good relationship with their kids. You know all their names, you know who their friends are, you know who goes to the parking lot after school for band practice.....or maybe not band practice.


Enter, my student George and the lesson on water. I don't have to mention this, but water is a pretty amazing little collection of molecules. Water is composed of hydrogen bonds, which are arguably some of the strongest intermolecular bonds on the planet. :)


So I'm describing hydrogen bonding, and asking the kids what happens when water drops onto a flat surface. Correctly they respond, saying that water forms a dome-like structure, further reinforcing proof that water holds itself together pretty decently. So then I ask the kids, "Well, what does surface tension mean to you?"


Innocently, George, a very intelligent and vocal student, replies, "Miss, is that like when a girl and a guy are in a room together and they like each other, but neither one of them wants to say anything, so they just stand there....." and he begins to trail off, because at this point all widened eyes are on him, as well as mine.


With a large grin and stifled laugh I answer back...."Oh George, not sexual tension. Surface tension." In my 2.5 years of teaching, I've never seen a face get redder than that. :)


Merry Christmas!