Can somepne please explain VSEPR theory to me???

Question

Give me some examples as well plz to help!! Thnx!

Answer 1

Valence shell electron pair theory says it is possible to predict bond angles around a central atom, like O in H2O, by supposing that all of the electron pairs in bonds and all of the nonbonding pairs repel one another until they are at a maximum distance from one another on a sphere.

In H2O, the Lewis structure has two ox electrons in each O-H bond, plus two xx pairs. So the four pairs of electrons mutually repel one another until they are oriented toward the four corners of a tertahedron, the bond angle H-O-H is 107deg.

In BF3, there are only three pairs, xo, for the three B-F bonds. So they repel one another until the three B-F bonds lie in a plane with a F-B-F bond angle of 120deg