NEET2006Chemistryd and f Block ElementsActual
More number of oxidation states are exhibited by the actinoids than by the lanthanoids. The main reason for this is:
Options
- Amore active nature of the actinoids
- Bmore energy difference between 5 f and 6 d orbitals than that between 4 f and 5 d orbitals
- Clesser energy difference between 5 f and 6 d orbitals than that between 4 f and 5 d orbitals
- Dgreater metallic character of the lanthanoids than that of the corresponding actinoids
Correct answer
C. lesser energy difference between 5 f and 6 d orbitals than that between 4 f and 5 d orbitals
Step-by-step solution
Actinides exhibit more number of oxidation states than lanthanides because of lesser energy difference between the 5 f and 6 d orbitals than that between the 4 f and 5 d orbitals. Related Theory Actinides have a very small energy gap between 5 f and 6 d orbitals, so they can easily form a variety of configurations and hence they are found to be stable in various oxidation states. Lanthanides are comparatively less electropositive than actinides and due to that reason, they are less reactive than actinides.