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.
Valence Electrons and Energy Levels. The electron is one of the most important factors in determining how an atom will react with another atom or molecule. A single electron can make all the difference in the properties of an atom. For example, sodium has one outer electron, located in that 3 s orbital.