Which of the following is not true?
a. An sp3 hybrid orbital may hold a lone pair of electrons
b. An sp3 hybrid may form a sigma by overlap with an orbital on another atom
c. The sp3 hybrid orbitals are degenerate
d. An sp3 hybrid orbital may form a pi bond by overlap with an orbital on another atom
d. An sp3 hybrid orbital may form a pi bond by overlap with an orbital on another atom is not true.
Explanation:
An sp3 hybrid orbital is formed by combining one s orbital and three p orbitals in a tetrahedral arrangement. These hybrid orbitals have a characteristic shape and orientation that allows them to form strong covalent bonds with other atoms.
Option (a) is true because an sp3 hybrid orbital has enough space to hold one or two electrons in addition to the bonding electrons.
Option (b) is also true because sp3 hybrid orbitals are capable of forming sigma bonds by overlapping with other atomic orbitals.
Option (c) is true because all sp3 hybrid orbitals have the same energy, and are therefore degenerate.
Option (d) is false because pi bonds are formed by the overlap of unhybridized p orbitals, not sp3 hybrid orbitals.