What Causes the Loud Boom That We Hear as Thunder

question 21

Multiple Choice

What causes the loud boom that we hear as thunder?

• A) supersonic movement of the leading end of a lightning bolt
• B) supersonic expansion of air heated by a lightning bolt
• C) supersonic movement of air pushed aside by a lightning bolt
• D) supersonic vaporization of water droplets as they flash into steam when heated by the lightning
• E) sudden generation of the sound wave as the "+" and "-" charges from the lightning connect