Question

Compare lanthanoids and actinoids.

Answer 1

Sr. No.	Lanthanoids	Actinoids
1.	The differentiating electron enters in 4f orbital.	The differentiating electron enters in 5f orbital.
2.	Binding energy of 4f orbitals are higher.	Binding energy of 5f orbitals are lower.
3.	They show less tendency to form complexes.	They show greater tendency to form complexes.
4.	Most of the lanthanoids are colourless.	Most of the actinoids are coloured. For example, U3+ (red), U4+ (green), \[\ce{UO^2+_2}\] (yellow)
5.	They do not form oxo cations.	They do form oxo cations such as \[\ce{UO^2+_2}\] \[\ce{NpO^2+_2}\] etc
6.	Besides +3 oxidation states, lanthanoids show +2 and +4 oxidation states in few cases.	Besides +3 oxidation states, actinoids show higher oxidation states such as +4, +5, +6 and +7.