Free Science Videos and Lectures

Potassium is a chemical element. It has the symbol K (Latin: kalium) and atomic number 19.
The name "potassium" comes from the word "potash", as potassium was first isolated from potash.
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This science video contains:
water, sparks, reaction, fire, potassium, alkali

The best physics lecturer Walter Lewin makes another wonderful physics demonstration after having read a lecture on batteries.

The battery he creates has a huge potential difference - 10 to 20...

This science video contains:
experiment, current, walter lewin, physics, demonstration, battery, emf, polarization, hydrogen, potential, sparks