[SOLVED] For each shape, how many nonbonding electron domains are there on atom A?

For each shape, how many nonbonding electron domains are there on atom A?

(i) trigonal planar

(ii) tetrahedral

(iii) trigonal bipyramidal

also,

which of the following elements will lead to an AF3 molecule with the shape in (ii): Li, B, N, Al, P, Cl

one more,

name on of the possible elements A those are expected to lead to the AF3 structure in (iii). Expain your reasoning.

thank you!