List of scientific demonstrations

Physics

Balsa wood bridge — demonstrates compressive strength and tensile strength, teaches engineering thinking
Egg drop competition — demonstrates compressive strength, teaches engineering thinking
Hand boiler — demonstrates vapour-liquid equilibrium and simple heat engine principles
Newton's cradle — demonstrates elastic collision, conservation of momentum, and conservation of energy
Gauss gun
Plate trick or Dirac belt trick — demonstrates spinors and the double cover of SO(3) by SU(2)
Prince Rupert's Drop — demonstrates supercooling and tensile stress
Self-siphoning beads — demonstrates momentum, energy and inertia
Water rocket — demonstrates conservation of momentum, conservation of energy, the gas laws and basic rocketry
Franklin bells — demonstrate electric charges
Oxford Electric Bell — an experimental electric bell that was set up in 1840 and which has run nearly continuously ever since
Wimshurst machine — an electrostatic generator
Shooting a candle through a plank
Foucault pendulum — demonstrates the rotation of Earth

Ammonia fountain — introduces concepts like solubility and the gas laws at entry level.
Barking dog reaction — demonstrates rapid exothermic chemical reaction
Blue bottle (chemical reaction) — demonstrates reduction and oxidation reactions, and chemical colour change
Chemical garden
Diet Coke and Mentos eruption — demonstrates bubble nucleation
Dry ice color show
Elephant toothpaste
Fizz keeper
Flame test
Magic sand — demonstrates hydrophobic substances
Mercury beating heart — demonstrates electrochemical redox reaction. and an effect of a non-homogeneous electrical double layer
Screaming jelly babies — demonstrates the energy within candy
Using liquid nitrogen to shatter a rose
Detonating a cloud of flour