Question

how do you draw the lewis structure for PBr3?

Answer 1

P has 5 valence electrons. Each Br has 7 valence electrons. This makes a total of 26 valence electrons. Put P in the middle. Attach the three bromines. You've used 6 of the 26 valence electrons in single bonds. You have 20 remaining. Each Br needs 6 while the P needs 2 more to become stable. This makes 20 which is how many you have remaining. Distribute the 20 as lone pairs and your structure is complete.

Answer 2

With difficulty on these boards. I will try.

<b>
Set up the molecule like this.
&nbsp &nbsp &nbspBr
&nbsp &nbsp &nbsp|
Br-P-Br

then put two dots (like this :) for each - or | shown, add two more .. at the bottom of P, then add six .. or : areound each Br. I hope this helps. </b>