General Science: Growing Crystals

This week we continued our investigations of solutions by making and examining crystals under the microscope. First we made saturated solutions of salt, copper sulfate, and borax. Then we placed a drop of each on a microscope slide, put them outside and waited for them to evaporate, and then used a microscope to look at the crystals that remained. We are also trying to grow some larger crystals. We'll see how they turn out next week...
One week later...
The good news is, Israel got a lot of rain this week. Great for growing crops, bad for growing crystals. We were hoping for our super saturated solutions (say that 5 times fast!) to evaporate, leaving behind beautiful crystals. Not likely to happen in the pouring rain. Next year we'll try this experiment in the late spring. In any case here's a picture of what you get when you SUCCESSFULLY grow large sugar crystals.

General Science: White powders

This week we continued our exploration of physical and chemical properties by investigating 4 different white powders: sugar, salt, corn starch, and baking soda. The physical properties we investigated included: how each one looks under the microscope and how each one feels. As for chemical properties, we combined the powders with vinegar and iodine and recorded the results. Finally we looked at whether any of the powders conduct electricity when dissolved in water.

The kids now have a comprehensive data sheet on these substances and their physical and chemical properties. If by chance, they should come into contact with some unknown white powder, making an identification should be a piece of cake!

One never knows when these skills and/or data might come in handy...