The element evolving two different gases on reaction with `conc. H_2 SO_4`.

The element evoloving two different gases on reaction with conc. H_(2)SO_(4) is :

The element evolving two different gases on reaction with conc sulphuric acid is

The element which evolves two gases on reacting with conc. H_2 SO_4 is

The element which evolves two gases on reacting with conc. H_(2)SO_(4) is

The element X on reaction with conc. HNO_(3) Forms two acidic oxides A and B of different shapes .element Z on reaction with conc . H_(2)SO_(4) Forms two acidic oxides A and D of different shapes .What are X and Z?