Open shell
From Wikipedia, the free encyclopedia
In the context of atomic orbitals, an open shell is a valence shell which is not completely filled with electrons or that has not given all of its valence electrons through chemical bonds with other atoms or molecules during a chemical reaction. Atoms generally reach a noble gas configuration in a molecule. The Noble gases (He, Ne, Ar, Kr, Xe, Rn) are not reactive and have configurations 1s2 (He), 1s22s22p6 (Ne), 1s22s22p63s23p6 (Kr), etc.
