(a) Name one metal in each case Which:
(i) exists as a liquid at room temperature,
(ii) can be found in nature in the uncombined state
(b) X and Y are 0.5 mol. dm(^{-3}) freshly prepared aqueous solutions of two salts of iron
(II) With excess sodium hydroxide solution, X gave a dirty green precipitate which was not obtained in the case of Y.
Explanation
a)(i) Caesium(Cs)
(ii) Gold (Au)
(b) Solution Y has been oxidized to iron (III) salts and it will give a reddish brown precipitate with excess sodium hydroxide.