Thursday, January 8, 2015

2015-01-08: Never to late to start again or learn something new.

Two for one today:

Liquid clear N2
is not diamagnetic
due to electron config.

Liquid blue O2
due to MO Theory is
paramagnetic.


I was never taught para- or dia-magnetism in high school or college.  I do remember by college chemistry professor telling us that liquid oxygen is magnetic and showing us a video of it [rather that doing the demo live which is a shame because I don't recall him ever doing a demo].  When I started teaching I learned about it from a demonstration book A Demo a Day published by Flinn Scientific and did the demo the next school year and explained it according to the demo book and via electron configurations.  However I was never able to understand why O2 is paramagnetic and N2 is diamagnetic: it part because I focused on electron configurations of the individual atoms and in part because it is explained much better by MO theory.  I actually have to give credit here to a Yahoo Answers for pointing me to MO theory, and then I went from there to work it out on my own.  Prior to reading that I read several really bad explanations, in addition to the bad ones I already knew that pointed to the electron configurations of individual atoms/elements and not their compounds/molecules.

Wednesday, September 26, 2012

Tuesday, September 25, 2012

2012-09-25: Hydrates Lab

Heating blue crystals
Hydrates become dehydrates
Striking color change


This lab happens to be one where the procedure and materials are different for AP vs General Chemistry, but it gets good results both ways.  The haiku above specifically refers to the general chemistry version of the lab where blue copper (II) sulfate is dehydrated into its white crystalline form.
As a side note, I feel really bad about leaving out my original middle line "Color changing chemistry" because I love the alliteration and the match with "crystals" in the first line, but alas I could not get anything to work with it and so I changed tack.

Monday, September 24, 2012

Friday, September 21, 2012

2012-09-21: Ends of the Universe


World end in fire?
Cosmology gives answers
Or world end in ice?

This is a lecture I love to give about the many different ways science tells us the end might come.  It also lets me reference an old saying I said way too often that everything I was doing was simply speeding up the coming of the Heat Death of the Universe.  If you are not versed in poetry [actually, I'm not either I just have  a few favorites] this haiku is my attempt to give tribute to Robert Frost's "Fire and Ice" that I use to end the lecture.

2012-09-20: Cannons




Small cannon goes pop
Projectile week finishes
Big cannon goes boom!





Wednesday, September 19, 2012