Why Sm²⁺, Eu²⁺ and Yb²⁺ ions in solutions are good reducing agents but an aqueous solution of Ce⁴⁺ is a good oxidizing agent?

One among the lanthanoids, Ce(III) can be easily oxidized to Ce(IV) (at. No. of Ce = 58). Explain why?

The +3 oxidation states of lanthanum (Z = 57), gadolinium (Z = 64) and lutetium (Z = 71) are especially stable. Why?

Which trivalent ion has the largest size in lanthanoid series?

What are the different oxidation states exhibited by the lanthanoids?

Which metal in the first series of transition metals exhibits +1 oxidation state most frequently and why? 

Write the electronic configurations of the elements with the atomic numbers 61, 91, 101 and 109.

Write chemical equations for the reactions involved in the manufacture of perman-ganate from pyrolusite ore.

Why is the + 2 oxidation state of manganese quite stable while the same is not true for iron? |Mn = 25, Fe = 26]

120.

What is misch metal (misch metal)? Mention its two important uses.