Beavers completed 3 experiments in their lodges to gain their badge. They made lava lamps, candle in a glass and oobleck
They learned that a fire needs oxygen to burn and when the oxygen runs out a vacuum pulled water into the glass. Those who lit the candle also ticked off part of their skills badge.
They also learned via our Lava lamps that the Carbon dioxide released from alkaseltzer tablets carried water through the oil and once reaching the surface the CO2 bubble popped meaning the water blob returned to the bottom.
Then they had lots of messy fun with oobleck (a non-Newtonian fluid which acts like a solid when hit, but a liquid when held)