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.
Sodium places its eleventh electron in a still higher energy level, the M shell. From sodium to argon, this shell is gradually filled with electrons until, once again, a maximum of eight is reached. Note that after the K shell with its maximum of two electrons, the maximum number of electrons in any other outermost shell is eight.