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.
At this configuration, electrons are at their the lowest energy level. This low energy level is called the Ground State. Atoms can absorb light energy and jump to a higher energy level. When they do so, they are said to be in an Excited state To do this