electricity

915

Lightning in clouds
A normal lightning strike to the ground is the result of the attraction between the negatively charged cloud and the positive charge on the ground below. What causes lightning to strike from one negatively charged cloud to another?

961

lighter
When I was growing up, lighters made a spark by rubbing a metal wheel across a flint (which was not really made out of flint.) Lighters like this one ignite the flame in a different way. How is the gas ignited?

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