All of us saw bright flashes in the sky when it is raining. These are the electric charges passing between a storm cloud and the earth. Such charges call lightnings. But they can be formed only under certain conditions.
In storm clouds, air masses move with a huge speed. They involve in the movement of a part of water, being in a cloud. At friction of air masses about water drops, there are static electric charges. Scientists found out that the top of a storm cloud is loaded with positive charges, and in its lower part there is an accumulation of negatively charged particles. The earth always has a positive charge. Negatively charged particles of a cloud want to direct to the positively charged earth. But it does not occur constantly as the earth's surface and a cloud is divided by a big layer of air which isolates these charges from each other. Air can divide charges only before achievement of a certain power by them. At accumulation of sufficient power in a storm cloud, negatively charged particles direct to the earth, I form at the same time huge sparks in the form of a lightning.
When the lightning hits into the earth, we manage to notice only one flash. In this visible flash there really is a category about ten lightnings. Negatively charged particles so quickly fly to the earth that several lightnings are perceived for one.
It is known that the lightning hits into the highest places. It occurs because the positive charge of the earth's surface collects always on heights. Therefore the first lightnings hit into the highest buildings or trees which are located some on the plain.
Lightning discharges are followed by allocation of huge heat. Temperature in a lightning reaches 16 thousand degrees. Therefore at hit of a lightning to the beach, on its surface sand bakes, forming glass.