The +3 oxidation state of Lanthanium (Z=57). Gadolinium (Z=64) and Lutetium (Z=71) are especially stable, Why ?

The stable oxidation state of Ce (Z = 58) is

The + 1 oxidation state of thallium is more stable than its + 3 state. Why ?

Why is + 4 oxidation state of titanium more stable than its +3 state? (Z = 22)

Why is + 2 oxidation state of manganese (Z=25) more stable than its + 3 oxidation state ?

Why +3 oxidation state of Fe (Z = 26) is more stable than its +2 oxidation state ?

Number of unpaired electrons in gadolinium (Z = 64) is 8/6.

Can lanthanum ion (Z = 57) exist in +4 oxidation state ? Justify your answer.

Why do transition elements show variable oxidation states ? Name the element showing maximum number of oxidation states among the first series of transition metals from Sc (Z = 21) to Zn (Z= 30).