today i was teaching a first year chemistry lab. the students were taking a unit where all of them had some background in basic chemistry, so usually they kind of know what to do. sure, i'll always get the silly questions of 'how do i use this (commonly used apparatus)?' or 'what is this (self-explanatory item)?', which is fine, because they're not supposed to know everything (and i definitely empathise with the students who come from relatively poor high schools, and have actually never encountered some of the items in the lab); but generally, the labs are pretty entertaining and it's fun for me to get around and teach some basic chemistry (i do love my basic sciences).
anyway, they were doing some classical organic experiment, which was the reduction of benzophenone to diphenylmethanol, followed by a purification process. the jokers were a handful today, and a group of them were being know-it-alls (which i normally do not mind, as long as they get their sch*t done and don't bother anyone else), which was particularly disruptive today because they didn't know what they were doing and were 'coaching' others to do the experiment wrongly. i just step in and correct everyone, so all is fine. one hour in, so far people are behind and some are looking sheepishly around in lost attempt to copy others. clearly a lot of them don't even know what's going on, which i attribute to not having read the pre-lab (this is pretty common, and i'll admit i wasn't the most studious when i was in their shoes, so all is still well).
two hours in, and so far so good, people are getting some yield, and others are... well, fluffing around. i make an announcement to please keep on track, which prompts some of the students to check the time and work a bit faster. all is well.
fifteen mins to go from the three hour lab. i tell people to start packing up, and of course, some of them would not do this in an attempt to complete the experiment, and some would continue to have their apparatus out in the last 2 minutes. i really get annoyed when i have to stay half an hour after the lab to clean up after them - it's not an issue of not being paid or anything, just that i have other errands to run and have appointments to keep on fridays, so i really cannot spare the time. that being said, i'm quite lenient and let them run 5 - 10 minutes late (i know some of the teaching staff will just walk out and refuse to mark anyone who submits late. i wonder if i'll turn into that begrudging person in the future).
anyway, so far, the lab has gone well, and of course someone would have to jinx it - in the final five minutes, no less. in quick succession, five pieces of broken glassware will echo down the lab corridors, and i am definitely peeved at this. they're first year students, granted, but the reason this was happening was because they couldn't be bothered with time keeping or heeding the continual suggestions, and were rushing at the final moments.
and then, all hell breaks loose (at least i would have imagined it to), when a student breaks a mercury thermometer and the contents spill on the lab floor. now, i have to emphasise that thermometers nowadays are pretty robust. they won't generally break if you let them fall on the floor, or accidentally knock them against the table / drawers etc. you really have to smash them with significant force to get the bulb to shatter. so i don't know what this student was doing (the experiment doesn't involve using a thermometer!) to have it happen, but c'est la vie. what surprised me (and dismayed me, mostly) is that none of the students in the proximity seemed to care. 'oh, look, elemental mercury on the floor. ho hum, business as usual'.
guys, i really don't have to spell this out to chemistry students. that sch*t is dangerous, son. stop working at that bench and clear the fsck out, mate. oh, man, i was having a minor heart attack at this moment, and everyone else (besides, perhaps the other demonstrator), seemed to care more about a measly 2 or 3 marks on their lab sheets than the possibility of dying or having mutant babies (ok, this is a lie, the amount of mercury in a thermometer even if you ingested in whole, will probably not be enough to kill you. but still, my point stands. heavy metals coming into contact with exposed skin is not as fun as, say a slayer concert).
anyway, it takes a good 10 mins for me to clear the scene (and there was this one student who kept trying to point out where pieces of broken glass / liquid mercury were, and i know she was trying to be helpful, bless her soul, but really i would have liked her to just move away from the area), and the next thing i realise is that we're 5m over time. half the class is still there.
a piece of me dies inside as i submit that i'll have to remain late, and though i won't miss my appointment, i have yet another (literal) mess to clean up after these students, who, as soon as they submit their handouts, walk ever-so-gaily into the sun while laughing *birds chirping in the background*. ok maybe not so much, but i'll allow myself a bit of a rant, regardless.
anyway, teaching is fun. you should do it for a living.