What is the molecular geometry and why?

Question

XeCl​2​ , ICl​3​ , TeF​4​ , PCl​5

what is the molecular geometry of these and why

Answer 1

First, draw the Lewis dot structures for each compound. It is difficult to do on this web platform, but I'll try to describe them the best I can.

XeCl2 would be Cl-Xe-Cl with 3 lone pairs around each Cl and 3 lone pairs around the Xe. This would be linear

ICl3 would be I as the central atom with there Cl atoms attached. Each Cl has 3 lone pairs and 2 lone pairs around the I. This would be T-shaped.

TeF4 would be Te as the central atom with 4 F atoms attached. Each F atom has 3 lone pairs and one lone pair on the Te. This would be seesaw shaped.

PCl5 would be P as the central atom with 5 Cl atoms attached. Each Cl atom has 3 lone pairs and no lone pairs on the P. This would be trigonal bipyrimidal.

You asked why the molecular geometry is what it is. If you mean "how do you tell", then the answer is you look it up (or memorize it) after drawing the correct Lewis dot and determining how many lone pairs on the central atom and how many bonding groups