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 :

The number of P $$-$$ O bonds in P₄O₆ is :

In KO₂, the nature of oxygen species and the oxydation state of oxygen atom are, respectively :