A group 13 element 'X' reacts with chlorine gas to produce a compound XCl₃. XCl₃ is electron deficient and easily reacts with NH₃ to form Cl₃X $$ \leftarrow $$ NH₃ adduct ; however, XCl₃ does not dimerize X is :

Among the oxides of nitrogen : N₂O₃, N₂O₄ and N₂O₅; the molecule(s) having nitrogen-nitrogen bond is / are :

When metal ‘M’ is treated with NaOH, a white gelatinous precipitate ‘X’ is obtained, which is soluble in excess of NaOH. Compound ‘X’ when heated strongly gives an oxide which is used in chromatography as an adsorbent. The metal ‘M’ is

The compound that does not produce nitrogen gas by the thermal decomposition is :