Shape of the molecules from the previous figure CANNOT result from simple s and p orbitals seen in general chemistry
To explain shapes (VSEPR) of organic molecules we assume that the s and p orbitals form hybrid atomic orbtials that separate the electron pairs more effectively in space. And put more electron density in the bonding region between the nuclei.
General rules we should consider for determining hybridization. These 3 are:
Both the sigma bonding electrons and lone pairs can occupy hybrid orbitals. The number of hybrid orbitals on an atom is computed by adding the number of sigma bonds and the number of lone pairs of electrons on that atom.
Use the hybridization and geometry that give the widest possible separation of the calculated number of bonds and lone pairs.
If two or three pairs of electrons form a multiple bond between two atoms, the first bond is a sigma bond formed by a hybrid orbital. The second bond is a pi bond, consisting of two lobes above and below the sigma bond formed by two p orbitals. The third bond of a triple bond is another pi bond, perpendicular to the first pi bond.