In Nitrogen family the H-M-H angle in the hydrides `MH_(3)` gradually becomes closer to `90^(@)` on going from N to Sb. This due to

In nitrogen family the H-M-H bond angle in the hydrides MH_3 gradually becomes closer to 90^0 on going from N to Sb. This shows that gradually:

The bond angle for the hydrides of Gr-15 elements decreases from NH_3(107^@) to SbH_3(91^@) . This is due to

Fifth group elements form hydrides to type AH_(3) . The hydrides have a lone pair of electrons. The hydries are reducing in nature and the reducing power is related to the stability of A-H bonds. The hydrides are covalent and low boiling. Their boiling points depends on their ability to from hydrogen bond and their molecular size which decide the intermolcular forces in the hydrides . The H-M-H bond angle of V group hydrides decrease from 107^(circ) to 90^(circ) for NH_(3) to SbH_(3) , this is due to:

Fifth group elements form hydrides to type AH_(3) . The hydrides have a lone pair of electrons. The hydries are reducing in nature and the reducing power is related to the stability of A-H bonds. The hydrides are covalent and low boiling. Their boiling points depends on their ability to from hydrogen bond and their molecular size which decide the intermolcular forces in the hydrides . The H-M-H bond angle of V group hydrides decrease from 107^(circ) to 90^(circ) for NH_(3) to SbH_(3) , this is due to:

Why is the H-O-H bond angle in H_(2)O smaller than H-N-H bond angle in NH_(3) ?

Why does bond angle decreases in the hydrides of nitrogen family while going down a group ?