This grow-your-own experiment that lets you grow crystals inside an egg shell. Be sure to get alum powder that contains potassium, or else you won't get any crystal growth. Adding drops of food dye to the growing solution yields some super cool crystals. A perfectly formed geode takes about 12-15 hours to grow, making this a great weekend project. Check out more of Art and Soul's gorgeous eggs over at their blog!
Ah, slime. It’s the one thing that parents across the UK have been being pestered to make, so why not turn it into a science activity? For our concoction, we mixed shaving foam, PVA glue and a little bit of air freshener (fabric conditioner can work too!), to create a slime that you can swirl, stretch and crack, providing hours of fun. Try changing the quantities to see how the mixture changes, and ask the kids to explain the differences.