Cool Science...A Reason to go to Plan B...



We all have plans. As teachers we plan every week and worry about time, depth, amount, types of assessment and state mandates. Most importantly, are the kids learning? We give it our best shot. Sometimes, we have to go to plan B.

     A couple of weeks ago an amazing discovery occurred. NASA discovered liquid water on Mars.(link is external) A fantastic book recently came out as well as the movie, "(link is external)The Martian".(link is external)  As luck would have it, I have some amazing colleagues who either have read the book or are in the process of reading the book. We have had some great discussions during lunch. Yes, there are parts that are fiction. Some students have to be reminded, we do not have people on Mars. We do not have a giant ion drive rocket that can get people to and from Mars. However, the author of the book did a great job of using many realistic scenarios to help a person survive on Mars. One scenario (I almost dropped dead) involves stoichiometry!
      Given the book, the movie and the discovery by NASA, I had to take some time to discuss the discovery. Provided the low pressure and cold temperatures of Mars, I was confused on how liquid water could be present?  \I think the key, according to NASA, is hydrated perchlorates in the Martian water. I think it has something to do with colligative properties. Even though we were nowhere near the topic of colligative properties and there were other things to do in the "plan", I wanted to come up with a quick and dirty demo for colligative properties. Years ago, I saw a great demonstration by Bob Becker at a Flinn workshop. He took a bottle of club soda, cooled it down with a salt and ice slurry, opened the bottle and as the carbon dioxide left the water, the water froze. I tried it several times and unfortunately got the bottle too cold and it broke. Then I had the idea to use two bottles. Cool both but leave one open as a control. I reasoned that the bottles were cold enough when the open bottle turned to ice. It worked like a charm (here is the video(link is external)). I tried to explain to the kids that even though the carbon dioxide in the water is what was causing the effect in the bottles, it is the salt in the water that is doing it on Mars. More importantly than liquid water, is the type of salt in the water...perchlorates. They have a bunch of oxygen. Hmmm...water, oxygen, weird conditions...what else could happen?


     We may not have gotten through the day's lesson with our little diversion, but most of the kids thought it was cool and some asked some good questions.  Also, I was excited and the kids thought I was a little nuts. So is anything wrong with that? Is it O.K. if students see that we are passionate about our jobs and sometimes a little nuts??? Within reason...sure.
     Still working on an inquiry lab about introducing moles. Still working on that. Until then, don't forget, if you have a great plan, but something amazingly cool comes along that you are passionate about, don't be afraid to share it with students. You never know who you might inspire.