Statements II, III and IV are true while I and V are false. In , the colour is due to charge transfer and not transition. Actinides exhibit a larger number of oxidation states than lanthanides because there is a very small energy gap between , and orbitals.

has two electrons (both unpaired). has twelve electrons (5 pairs and 2 unpaired). Both and with 2 unpaired electrons each, have the same colour. electrons in actinides are less effectively shielded resulting in quenching of orbital contribution of magnetic moments. So their magnetic moments are less than theoretically predicted values. Though, and -orbitals have similar shapes but is less deeply buried than . Hence, electrons in -orbital can participate in bonding to a far greater extent than electrons in -orbital. Therefore, shielding of -orbital is more than -orbital.