I have a pretty good understanding of VSEPR theory and how to predict bond angles etc.
However, one thing bugs me.
Supposing I have NH3.... I know that there is only one lone pair and that bond angle is 107.3 degrees.
Now, what if I were asked to predict the bond angle of PH3 ?
I know it is around 104 degrees.
My question is why this decrease in bond angle for these two similar compounds containg elements inn the same group ?
Does have to do with the electronegativity ?