Lightning over St-Laurent River on a stormy night in Quebec.
Image Credit: Jp Marquis
In massive storm clouds, the friction between large particles composed of many atoms builds up a large separation of electric charge and creates voltages approaching 100 million volts. When the voltage becomes this large, it can cause an explosive electric discharge observed as a lightning bolt. The heat generated during a lightning strike is hotter than the surface of the Sun, and this heat is the source of the brilliant white-blue flash that we see.