The d and f - block Elements

In what group of the periodic table the element will found having electronic configuration: $$[Xe] 4f^{14}5d^46s^2$$?
Among the transition elements the element with lowest melting point belongs to:
(i)  A powered substance $$(A)$$ on treatment with fusion mixture ($$K_2CO_3$$ and $$KNO_3$$) gives a green coloured compound $$(B)$$.
(ii)  The solution of $$(B)$$ in boiling water on acidification with dilute H$$_2$$SO$$_4$$ gives a pink coloured compound $$(C)$$.
(iii)  The aqueous solution of $$(A)$$ on treatment with $$NaOH$$ and $$Br_2$$ - water gives a compound $$(D)$$.
(iv)  A solution of $$(D)$$ in conc. $$HNO_3$$ on treatment with lead peroxide at boiling temperature produced a compound $$(E)$$ which was of the same colour as of $$(C)$$.
(v)  A solution of $$(A)$$ on treatment with a solution of barium chloride gave a white precipitate of compound $$(F)$$ which was insoluble in conc. $$HNO_3$$ and conc. $$HCl$$.
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Iron forms halide salts by reacting the metal directly with halogen. $$Fe{I}_{3}$$ does not exist. $$Fe{F}_{3}$$ is white solid inspite of five unpaired electrons with $${d}^{5}$$ congfiguration. $$Fe{Cl}_{3}$$ is soluble in water and is used as a mordant in dyeing industry.