Homeschool Science: Ice Skull versus Salt

Too many holidays, too little time!

ESPECIALLY after the advent of Pinterest, my planner is absolutely chock-full of dozens and dozens of fun, beautiful, and educational project that the girls and I would absolutely love to do for every single holiday that you can think of. Now the problem is that there just isn't enough time to do them all!

In October, we did autumn projects and Halloween projects. We colored and cut out paper garlands with jack-o-lanterns and skulls on them, carved pumpkins, made garlands of autumn leaves using paint chips and crayon boxes, baked pumpkin bread and pumpkin chocolate chip cookies, sewed Halloween costumes, did leaf rubbings and pressed leaves and coated them in beeswax, baked mummy dogs, and assembled giant laminated paper skeletons and hung them on the porch. We did NOT make haunted candy houses, or carve turnips, or assemble a bone garland or a gourd garland or a candy corn garland, or play with dry ice, or bake jack-o-lantern pizza, or paint pumpkins, or make eggshell ghosts, or even half of the other billion wonderful projects in my Halloween Craftacular pinboard.

And even though Dia de los Muertos was practically my favorite holiday back when I was living in Texas--dancing skeletons, sugar skulls, tissue paper flowers, Mexican beer!--it's going to have to be celebrated next year, because this year it just passed us by in our post-Halloween candy coma.

Of course, that doesn't mean that we can't do any of the awesome projects that I'd had planned--they're just regular old projects now, not festive thematically-appropriate seasonal projects.

And that's how this big old ice skull, made from a mold that I bought a few weeks ago from Joann's at 65% off, is in our regular rotation these days not as a Dia de los Muertos or Halloween science project, but just as a regular old fun science project:

Any big ice cube will work for this project, although you have to admit that the skull is pretty gruesome! I've also made the girls icebergs by freezing water in a mixing bowl, however, and that kind of simple ice mold will work just as nicely here.

You also need liquid coloring--we use liquid watercolors, because I'm a sucker for those bright, saturated colors!--and plenty of cheap salt.

Liquid watercolors alone, simply because they, themselves, are above the freezing point, will assist in melting the ice mold in interesting ways as you dribble, drop, and spoon them on, but the best fun comes from adding salt into the play. Salt lowers the freezing point of water--for instance, a particular salt solution might lower the freezing point of the water that it's mixed in from 32 degrees to, say, 20 degrees. When you add it straight to ice, then it hastens the ice's melting, because room temperature is now even farther above the ice's freezing point than it used to be.

This is all fun because the ice melts the fastest right where you add these things:

See? Gruesome!

Of course, it's also fun just to scoop and pour and mix and generally make a big mess:

Besides, who wouldn't appreciate some crayon skulls and x-ray viewing and plaster of Paris skeleton making mixed in with the handprint turkeys and pumpkin pie baking and walnut shell Mayflowers this season?

It's turning out to be such an interesting autumn!