History homework help

1. Why do unshared (lone pair) of electrons affect the shape (angles) in a molecule?2.In your lab, the molecules CO2, CH4, and H2CO all had four bonds (8 shared electrons) but very different geometries.  Explain why they were different.3.Based on what you have learned, predict the shape of each of the following (draw an electron dot picture and use the names for the shapes as discussed).  Give your reasoning for why and how you determined the shape. a. NF3b. H2S c. Cl2O