Khan Academy
How We Know About the Earth's Core
The big question is, how do we know about the composition of the earth's core? Sal explains that at 105 degrees from the source point of an earthquake, the phenomenon of the p wave shadow zone leads us to conclude that the waves are...
Curated OER
Waves
The nature of waves is revealed through a tank of water and computer animations. Your physics learners will be illuminated by viewing this explanatory video.
Curated OER
Particles
A female narrator takes your class on a journey through the history of atomic theory. Not only are protons, neutrons, and electrons introduced but quarks and leptons are too. You will find this most appropriate for viewing in a high...