### The d and f - block Elements

goals
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. $HCl$.
Yellow cake ' an item of smuggling across border s
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.