Make a cloud in a bottle
What you see is condensation. The air inside the water bottle is moist, and there are usually still some drops of water in the bottle. Twisting the bottle compresses and heats the air inside, helping to evaporate that bit of water. When you pop the cap off, the air abruptly decompresses and cools, causing tiny water droplets to condense and form a miniature cloud.
0:32 How to Make a Smoke Waterfall
Smoke is heavier than air but normally floats upwards because it is hot. The tube gives the smoke enough time to cool down, after which it doesn't rise up, but instead falls to the floor like a waterfall.
1:07 Smoke Bubbles Experiment
Using dry ice and bubble soap easy to do at home and very cool
1:35 Whoosh Bottles Experiment
2:24 Smoke Rings Experiment (Air Canon Smoke Ring)
3:03 Smoke vs Bakin soda and vinegar experiment
3:36 Traveling Flame Science Trick
This fire trick is based on how candles work. When you light a candle, the heat from the flame vaporizes the candle wax. When you blow the candle out, vaporized wax briefly remains in the air. If you apply a heat source quickly enough, you can ignite the wax and use that reaction to relight the wick of the candle. Although it looks like you're lighting the candle with smoke, it's really just the wax vapor that ignites. Soot and other debris from the flame aren't ignited.
