1 4,18. 2  Shingles in caused by the same virus that causes chickenpox-varicella-zoster virus. 3  Shingles is a painful infection of the nerve supplying an area of skin and is accompanied by a localised skin rash.
The electrons on the outermost energy level of the atom are called valence electrons. The valence electrons are involved in bonding one atom to another. The attraction of each atomâs nucleus for the valence electrons of the other atom pulls the atoms together.
When electrons gain or lose energy, they jump between energy levels as they are rotating around the nucleus. For example, as electrons gain energy, they might move from the second to the third level. Then, as they lose energy, they might move back to the second level or even to the first energy level. Only a certain number of electrons can be in an energy level at the same time. The photon shown in the graphic can be considered a small bundle of energy. (For more information on atoms, you may want to review the materials on magnetism.) Review: Electrons spin and rotate around the outside of the nucleus.