The correct statement regarding the 3py orbital is:
The number of spherical nodes =n−l−1 and the number of nodal plane =l
For 3py orbital, the number of spherical nodes =3−l−1=1 and the number of nodal plane =l=1
So, XZ is only a single nodal plane for 3py.
The magnetic quantum number for 3py may be +1,0 or−1.
A single maxima is obtained when a curve is plotted between 4πr2R2(r)vs r.