A Metal, M which Is Not Affected By Strong Acids And Strong Bases But Dissolves In Aqua-regia Forms MCl3 which Is Used For Toning In Photography. The Metal M is

Hg­₂Cl₂ ionises as ……... and cation has ……… unpaired electron (s).

Transition metals form alloys easily. The reason for this is

An inorganic compound on strong heating gave a blackish brown powder and two oxides of sulphur. The powder was dissolved in HCl when a yellow solution was obtained which gave a blood red coloured solution with thiocyanide ions. The inorganic compound may be

The species that undergoes disproprotionation in an alkaline medium are

In industrial smog, Cu corrodes to

IE₁ of Cu (3d¹⁰ 4s¹) is less than that of Zn (3d¹⁰ 4s²) because it is easy to remove an electron from a half-filled s-orbital as compared to fully-filled s-orbital. However, in case of IE₂, the electron is lost from 3d orbital of Cu and 4s orbital of Zn and loss of electron from 4s orbital is easier as compared to fully-filled 3d orbital.

An inorganic compound (A) gave the following reactions

(i) The compound on heating gave a residue and a gaseous mixture of NO₂and O₂.

(ii) The aqueous solution of (A) gave a white precipitate with sodium chloride solution. The precipitate dissolves in NH₄OH. The compound (A) is

Silver nitrate produces a black strain on skin due to

Transition elements exhibits variable valencies because they release electrons from the following orbits

The transition elements are more metallic than the representative elements because they have