Lithium, sodium, and potassium undergo reactions with water.
Two liters of warm water in large pyrex vessel, covered with fine mesh stainless steel screen, is on a stool close by in-floor vent hood. Add a few drops from the phenolphthalein indicator...
A balloon is dropped in boiling water, and another balloon is cooled with liquid nitrogen to demonstrate the effect of temperature on volume of gas in a balloon.
A 4 liter beaker on a hot plate, with a liter of water boiling within. A prepared balloon...
Two small closely mounted bulbs simulate resolution problems.
What it shows:
The ability to resolve two closely separated stars depends upon the aperture size of the observing instrument. Here two tiny bulbs represent stars that are barely resolvable by...