CK-12 Foundation
Ck 12: Chemistry: Electron Shielding
[Free Registration/Login may be required to access all resource tools.] Covers electron shielding, s orbital influence on shielding, paired electron spin and shielding.
CK-12 Foundation
Ck 12: Chemistry: Transition Metal Ions
[Free Registration/Login may be required to access all resource tools.] Covers transition metal, ionization of transition metals, and inner shell electrons.