posted by Lola .
How do the lewis structure and the positions of valence electrons affect the shape of the covalent compound?
This is something for my lab
The idea is that the electrons are arranged in space so that the electrons are as far from each other as they can get but still attracted to the nuclei. For regions of high electron density we have tetrahedral for four, trigonal planar for three, and linear for two. You can read more about this starting with VSEPR theory (Valence Shell Electron Pair Repulsion).