What causes lightning and thunder?

[Grade 9 student at Kamwala Secondary School in Lusaka]

Dear Zambia,

Friction between water droplets and air separate electric charges into positive and negative, with one set rising to the top of the clouds and others descending to the bottom. This separation of charges results in huge electric potential, such that air, which is normally an insulator, becomes a conductor and the clouds discharge, emitting a thunderous stroke of light and sound.

[Guest]

[quote="Grade 9 student at Kamwala Secondary School in Lusaka"]Dear Zambia,

Friction between water droplets and air separate electric charges into positive and negative, with one set rising to the top of the clouds and others descending to the bottom. This separation of charges results in huge electric potential, such that air, which is normally an insulator, becomes a conductor and the clouds discharge, emitting a thunderous stroke of light and sound.[/quote]