The flame test lab went so well last week that I decided I needed to do it as a demo for the younger class this week. But to understand why they were seeing different colors for different chemicals we had to talk about atoms and electrons. So we started out by watching the Brainpop on atoms and then this great TedEd video “Just How Small is an Atom?”
I also showed this music video by They Might Be Giants,
and Daniel Radcliffe singing the elements song.
I then asked the kids, if atoms are so small and mainly empty space… how do we know so much about them? We can’t see them. I talked a bit about the history of the atomic theory and used part of slideshow I found on middleschoolscience.com that is attributed to Mr. Enn and mentions that more is available on teacherspayteachers.com.
After the slideshow I passed out diagrams of an atom with empty shells and random element cards (with atomic number less than 19) from my Photographic Card Deck of The Elements – I love these cards. The kids then wrote the abbreviation for their element on the diagram and wrote the number of protons in the nucleus with a +p. Then they filled in the electron shells, starting in the center, until they had the right number of electrons (same number as protons). This is a fairly simple activity but the kids always enjoy it and ask to do more. Most kids do at least 3 different elements yesterday. (I just remembered where I found this activity, its from Tyler Dewitt’s video at the bottom of this post. He steps through putting electrons in shells so I made blank drawings just like the ones in the videos and the kids could follow along).
I also gave them a lift the flap model of an atom from Atomic Structure Interactive Graphic Organizers for Chemistry and Physical Science Notebooks by Bond With James (teacherspayteachers). I actually wish I had used the one where they just write the name on the pictures because the flaps were pretty hard to cut out, even when I had started them with an exacto knife.
For the last 20 minutes of class we played with fire… well, I played with fire and they watched. We had wooden skewers soaking in the chemical solutions that I made last week, and pulled them out one at a time to put in the flame of the butane burner to produce colored flames. Lots of ooohs and aahhhhs. The kit to do this lab can be purchased at homescience tools but I did the experiment a little differently then the included instructions. I followed the flame test lab instructions by Ian Guch.
Tyler’s Dewitt’s video on valence electrons: