What do you expect the nature of hydrides is, if formed by elements of atomic numbers 15, 19, 23 and 44 with dihydrogen? Compare their behaviour towards water.

Explanation

(i) Element with Z = 15 is phosphorus (a non-metal). It will form a covalent hydride, `PH_(3)`.
(ii) Element with Z = 19 is potassium (an alkali metal). It forms a saline hydride, `K^(+)H^(-)`.
(iii) Element with Z = 23 is vanadium (a transition metal). It would form a metallic or interstitial hydride, `VH_(0.56)`.
(iv) Element with Z = 44 is ruthenium (a group 8 element). It does not form any hydride.
Among these hydrides, only potassium hydride reacts with water as shown below.
`2KH(s) + 2H_(2)O(l) to2KOH(aq) + 2H_(2)(g) `