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.
The electrons that are found in the outermost occupied orbitals of an atom, known as valence electrons, do not always remain in the same orbital or energy level, as they are able to absorb energy from heat or light. When a valence electron absorbs energy, it enters what is known as an excited state. The excited state can commonly take the form of the electron jumping from its original energy level or orbital, also known as the ground state, to an empty orbital of a higher energy