Why do Zr and Hf exhibit similar properties ?

Explain the following: (a) Europium (II) is more stable than cerium (II) (b) Zr and Hf exhibit similar properties. ( c) Scandium forms no coloured ions, yet it is regarded as a transition metal.

(a) Why do Zr and Hf have similar properties? (b) What happens when K_2Cr_2O_7 is treated with H_2SO_4 and NaCl solution ? (c) Why do transition metals form alloys easily?

(a). Of the lanthanides, cerium (Z=58) forms a tetrapositive ion, Ce^(4+) in aqueous solution. Why? (b), The +3 oxidation states of lanthanum (Z=57) , gadolinium (Z=64) and lutetium (Z=71) are especially stable. Why? (c). Why Zr and or Nb anbd Ta exhibit similar properties ? (d). Which oiut of the two La(OH)_3 and Lu(OH)_3 , is more basic and why?

Why Zr and Hf or Nb and Ta exhibit similar properties? Or Zirconium (atomic number40) and hafnium number 72) occur together in minerals and they exhibit similar properties. Give reasons.

Why do elements with similar properties occur in the same group?

Isotopes exhibits similar

Beryllium and aluminimum exhibit many properties which are similar . But, the two elements differ in