We started class by watching a couple of videos about water and phases of matter:

What Is An Ice Bomb? (Mr. Wizard)

States of Matter by Veritasium

Why does ice float in water? – George Zaidan and Charles Morton

I’m always a bit annoyed when science curriculum say there are only 3 phases of matter, gas, liquid and solid, so I showed this video on plasma and I told the students about liquid crystals which share characteristics of both solids and liquids.

Plasma, The Most Common Phase of Matter in the Universe – SciShow

For this class we used the lab, Chapter 2, Lesson 4: Changing State – Freezing  from the ACS Middleschool Chemistry curriculum. Students put rock salt and ice layers in an metal soup can.  The salt lowers the freezing point of water so the temperature of the salt/ice img_4709mixture will drop below zero degrees Celsius. Once the students observed ice forming on the outside of the can they measured the temperature of the ice/salt mixture.  While waiting for ice to form on the cans the students made water molecules out of stryofoam balls and toothpicks.  They also cut and pasted the lab sheets into their notebooks and filled out a table on the properties of water molecules in their liquid vs solid form.

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