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.
You know that the valence electrons are defined as being the electrons located on the highest energy level of that atom, which is given by the principal quantum number, n. Notice that, in iodine's case, the highest energy level is n=5. You have two subshells occupied with electrons on this energy level, 5s2 and 5p5.