<P> The order of the orbitals per shielding strength is: </P> <Dl> <Dd> s> p> d> f> g (\ displaystyle \ mathrm (s)> \ mathrm (p)> \ mathrm (d)> \ mathrm (f)> \ mathrm (g)) </Dd> </Dl> <Dd> s> p> d> f> g (\ displaystyle \ mathrm (s)> \ mathrm (p)> \ mathrm (d)> \ mathrm (f)> \ mathrm (g)) </Dd> <P> In hydrogen, or any other atom in group 1A of the periodic table (those with only one valence electron), the force on the electron is just as large as the electromagnetic attraction from the nucleus of the atom . However, when more electrons are involved, each electron (in the n - shell) experiences not only the electromagnetic attraction from the positive nucleus, but also repulsion forces from other electrons in shells from 1 to n . This causes the net force on electrons in outer shells to be significantly smaller in magnitude; therefore, these electrons are not as strongly bonded to the nucleus as electrons closer to the nucleus . This phenomenon is often referred to as the orbital penetration effect . The shielding theory also contributes to the explanation of why valence - shell electrons are more easily removed from the atom . </P>

Order of screening effect s p d f