Arrange the following in decreasing order of bond angle 1) NH3 2) PH3 3) AsH3 4) SbH3 with proper reasoning
NH3 > PH3 > AsH3 > SbH3 > BiH3
N is a smaller central atom, and additionally, it is more electronegative. It attracts all the electrons closer to itself.
At smaller distances, the repulsion between bond pair electrons increases. There will be repulsion between H-H atoms.
When the central atom is big enough that the H-H distance is large compared to the size of the H atom, the steric effects grow vanishingly small. Hence, the decrease in bond angle from say, AsH3 to SbH3 will be negligible.
You have rated this answer /10