Answer to Question #53494 in Inorganic Chemistry for manisha
why the hydrides of nitrogen is stable while the hydrides of other element of same group are not stable. explain
Stability of hydrides decreases from N to Bi due to the increase in the difference between electronegativities of hydrogen and corresponding element. This leads to polarization of the E-H bond which becomes more ionic than for element in the upper period. At the same time, the stability decreases in order of increasing atomic radius. Since a nucleus of central atom with larger radius attracts bonding electrons weaker, the E-H bond becomes less stable. In addition impact of the inert pair effect increases from N to Bi, when completed electronic sublevels interact with valence orbital decreasing its energy. This leads to low availability of valence electrons and weak E-H interaction.