The Return of the Chemistry Cave!

Some of you may remember that I had a Chemistry Cave display last summer.  I decided to bring the display back this year for our science filled summer and do even more experiments!

Experiment 1: Stalactites and Stalagmites

If you remember last year's Cave, you will also remember the infamous Stalactite and Stalagmite Growing Fail.  If you don't, let me give you the short version: the experiment didn't work.  I decided that this summer, I WOULD grow stalactites and stalagmites, no matter what! 

Here's our set up:

Two cups, one filled with Epsom Salt that had been dissolved in water, with a string stretched between them.  The desired outcome: stalactites and stalagmites growing from the string!

I waited.  I waited.  I waited.

Nothing.  Once again, I was defeated.

I will never attempt this experiment again.


Experiment 2: WASH YOUR HANDS!!! 

This next experiment was done by Cassie and our Tweens during a Tween Wednesday program.  They were talking about germs and why we should wash our hands.  For the experiment, they had two pieces of an apple.  For Apple A, as soon as they cut the piece from the apple, they sealed it up in a plastic bag.  For Apple B, they passed the slice around the group, making sure everyone had a chance to hold the apple (it even briefly hit the floor!), before placing it in a plastic bag.  They left the apples to sit to see what happened over a few days.

Remember, Apple A is the "clean" apple and Apple B is the one that was passed around the group.

Do you need to wash your hands now?

Experiment 3: The Bouncing Egg

Yes, you can make an egg bounce!  I placed a regular egg in a bowl, covered it with vinegar, and let it hang out for 24 hours.

Ok, so not much to see.  After 24 hours, I took the egg out of the vinegar and the shell was gone!  The egg also felt a little swollen and it felt SUPER GROSS!!!  But would it bounce?

 

 IF I had followed the instructions and dropped the egg from a height of 3 inches or less, I'm sure it would have bounced.  Good thing I did this over the sink!

 

 I hope you've enjoyed our Chemistry Cave!

Alyssa




 

The Chemistry Cave

This summer, I've turned one of our display cases into the Chemistry Cave.  I've been placing different experiments in the "cave" throughout the summer.  The experiments have come from the book Cool Chemistry Concoctions: 50 Formulas that Fizz, Foam, Splatter, and Ooze by Joe Rhatigan and Veronika Alice Gunter. 

The first experiment, growing stalactites and stalagmites, was an EPIC FAIL.  It seemed simple enough: mix epsom salt and hot water in a cup, let a string tied to two paper clips soak in the solution, get another cup to place one of the paper clips in, and wait for the stalactites and stalagmites to form.  I waited a whole week and NOTHING happened!

 I tried the experiment again and, once again, nothing happened.  I went to take the cups out of the case and found a surprise. 

A crystal had formed in one of the cups!  Instead of traveling down the suspended string to make stalactites, the solution stayed in the cup and formed this lovely crystal.

Inspired by the crystal, I decided to grow crystals for the next experiment.  This experiment involved dissolving alum (found in the baking aisle of most grocery stores) in hot water and letting it set overnight to form seed crystals.  Then, you tie one end of a string to a crystal and the other to a pencil and hang the crystal in the jar to let it keep growing.  I forgot about the whole string and pencil bit and just left everything in the jar.  A week has gone by and here's what we have.

   Lots of tiny crystals! 

 

 

I've added the crystals to another mixture of alum and water.  What do you think will happen now?  Stop by the library to see what the crystals do next!

 

 

Enjoy Summer Reading!

Alyssa