Answer:
1. Electrons surrounding a nucleus are attracted to the protons within it because electrons and protons have opposite charges. Electrons closest to the nucleus are attracted with such a force that they can’t escape from the atom. These electrons tend to shield the protons from electrons that are farther away because electrons have the same charge and repel each other. Electrons that are farther away have less attraction to the protons within the nucleus and are more likely to be detached from the atom.
2. Electrons can be transferred from atoms of one body to atoms of another body through friction. This can occur when one body is rubbed against another or when a liquid flows across a solid. In either case, one body may be given a positive charge while the other body is given a negative charge of the same magnitude. Both charges are developed at the same time. Electrons can also be transferred from one body to another when a charged body comes into contact with an uncharged body. The electrons move in the direction that will equalize the charges; thus, the uncharged body will be given the same charge as the charged body.
3. Free electrons move from points of negative charge to points of positive charge. When these electrons move freely from one point to another with little resistance, the material they’re traveling through is said to be a conductor. Conductors have a large number of free electrons. Insulators, on the other hand, have very few free electrons and offer great resistance to the movement of these electrons. Electric charges produced on one end of a body composed of insulating materials will most likely not spread throughout the body. In a conductor, this charge would spread throughout the entire body. Metals are generally conductors; oils, rubber, air, porcelain, and plastics are good insulators.
4. Lightning is produced by the rapid transfer of free electrons when one of the following conditions exist:
One part of a cloud is positively charged and a neighboring part of the same cloud is negatively charged.
A positively charged cloud comes near a negatively charged cloud.
A cloud with either a positive charge or a negative charge comes near the earth.
