Why do actinoid elements show wide range of oxidation states ?

How do you prepare : (i) k_(2)MnO_(4) from MnO_(2) ? (ii) Na_(2)Cr_(2)O_(7) from NaCrO_(4) ? (b) Account for the following : (i) Mn^(2+) is more stable then Fe^(2+) towards oxidation to + 3 state. (ii) The enthelpy of atomization is lowest for Zn in 3d series of the transition elements. (iii) Actinoid elements show wide range of oxidation states.

Account for the folloiwng: Actinoid elements show wide range of oxidation state.

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).

(i) What are transition elements ? (ii) Why do transition elements show variable oxidation states ?

Why do transition elements show variable oxidation states? Write the name of a 3d-series element that exhibits maximum oxidation states.

Why do transition metals show a number of oxidation states ? Explain.