Answer to Question #84658 in Inorganic Chemistry for Adarsh

Question

Even though actinides show similar variations in magnetic properties as that of
lanthanides, their magnetic properties are more complicated. Explain.

Answer 1

Lanthanoids are involved in the filling of 4f-orbitals whereas actinoids are involved in the filling of 5f-orbitals. The binding energy of 4f-electrons is comparatively less than that of 5f-electrons. The shielding effect of 5f-electrons is less effective as compared to that of 4f-electrons.

The paramagnetic properties of lanthanoids can be easily explained but this explanation is difficult in case of actinoids. Lanthanides are non-radioactive in nature except promethium whereas all actinide series elements are radioactive. Lanthanides do not have a tendency to form oxocations, but several oxocations of actinide series exist. The compounds formed by lanthanides are less basic on the other hand the compounds of actinides are highly basic.