AS 020 09-Jul-12. BASIC IDEAS Shapes of molecules and ions depends on total number of electron pairs around the central atom. Two types of electron pairs:
1 VSEPR Theory In any molecule or ion there are regions of high electron density: Bonds (shared electron pairs) Lone pairs (unshared electrons) Due to.
1 Trigonal Bipyramidal Electronic Geometry: AB 5, AB 4 U, AB 3 U2, and AB 2 U 3 If lone pairs are incorporated into the trigonal bipyramidal structure,
