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.
Not all of the electrons in an atom make chemical bonds. Most atoms form bonds using only the electrons in the outermost energy level. An electron in the outermost energy level of an atom is a valence electron. The models in Figure 3 show the valence electrons for two atoms. Figure 3 Counting Valence Electrons