Hydrides and H2O

In case of the hydrides H_2O, H_2S, H_2Se and H_2Te the acid strength of aqueous solution of equimolar concentration.

Assertion :- Oxidation state of Hydrogen is +1 in H_(2)O while -1 in CaH_(2) . Reason :- CaH_(2) is a metal hydride and for metal hydrides, hydrogen is assigned the oxidation number of -1 .

The hydride ions (H^-) are isoelectronic with

The decreasing order of the boiling points of the following hydrides (i) NH_3 (ii) PH_3 (iii) AsH_3 (iv) SbH_3 (v) H_2O is

The correct statements(s) regarding hydrides (H_(2)E) of group -16 is/are