Lightning is the emission of light due to electricity discharging from cloud-to-cloud or from cloud-to-ground.
Lightning
Lightning is the emission of light due to electricity discharging from cloud-to-cloud or from cloud-to-ground. This electrical discharge results from the buildup of positive and negative charges within a thunderstorm. In a calm sky, the positive and negative charges are all mixed up. However, during a thunderstorm, rapidly rising air interacts with rapidly falling air to create separately positive and negative charged areas within the cloud. The positive areas are where protons are located, while the negative areas are where the electrons are located. Protons are important parts of atoms that do not typically float around on their own, unless you are causing a nuclear reaction by splitting the atom. Electrons, however, can be free floating. Protons are usually located at the top of the thunderstorm. Electrons are usually located at the bottom of the thunderstorm, or the bottom of a cloud. During a thunderstorm, the earth has a positive charge. Air usually acts as an insulator, but when the charge builds up to a level that exceeds its ability to act as an insulator, the result is a spark we see as Lightning.