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.
1 When the third energy level has 8 electrons, the next 2 electrons go into the fourth energy level. 2  The electrons in the energy level farthest from the nucleus are called valence electrons. 3  Atoms in the same column (group) in the periodic table have the same number of valence electrons.