They are formed only in covalently bonded atoms. Hybrid orbitals do not exist in isolated atoms.The following ideas are important in understanding hybridization: Understanding Atomic Orbital Hybridization

The new orbitals that result are called hybrid orbitals. This process of combining the wave functions for atomic orbitals is called hybridization and is mathematically accomplished by the linear combination of atomic orbitals. When atoms are bound together in a molecule, the wave functions combine to produce new mathematical descriptions that have different shapes. The mathematical expression known as the wave function, ψ, contains information about each orbital and the wavelike properties of electrons in an isolated atom. The hybrid orbitals obtained through sp 3 hybridization overlap with the 1 s orbitals of the hydrogen atoms to produce a methane molecule that has tetrahedral geometry and 109.5° bond angles. The mixing of the 2s and three 2 p orbitals generates four equivalent sp 3 hybrid orbitals that each can hold one unpaired electron.

The carbon atom has four valence electrons. Sp 3 hybrid orbitals form the tetrahedral shape of a methane molecule. Three of these orbitals, one s, and two p orbitals, mix to produce a set of three sp 2 orbitals, each containing one unpaired electron, and one 2 p orbital remains unhybridized.Įach of these overlap with a 1 s orbital from a hydrogen atom to form three sigma bonds.Ī molecule with sp 2 hybridization has a trigonal planar geometry with 120° bond angles. Boron has one 2 s and three 2 p valence orbitals and three valence electrons. The trigonal planar geometry boron trihydride can be explained by sp 2 hybridization. Therefore, beryllium fluoride exhibits sp hybridization, is linear, and has a 180° bond angle. The half-filled hybrid orbitals undergo end-to-end overlap with orbitals from the fluorine atoms to form two identical covalent bonds, which are also known as sigma (σ) bonds. For clarity, these orbitals are often shown without the minor lobes.

Thus, the electron probability density is highly concentrated in a directional lobe, which leads to a more effective overlap with the orbitals of other atoms. The hybrid orbitals have a different shape from their constituent atomic orbitals with one lobe that is significantly larger than the other. This leaves two unhybridized p orbitals and produces two sp hybrid orbitals, named for the original atomic orbitals. The s orbital mixes with one of the empty p orbitals to create orbitals that contain unpaired electrons available for bonding. The beryllium atom has two valence electrons found in its 2 s orbital in the ground state. The initial number of atomic orbitals and the number of hybrid orbitals generated is always the same.īeryllium fluoride is a linear molecule. Some atomic orbitals involved in bonding recombine to form new orbitals whose shapes are a hybrid of the originals. Valence bond theory helps to explain this molecular geometry through the hybridization, or mixing, of atomic orbitals. S and p orbitals overlapping to form covalent bonds cannot yield the various molecular shapes in the VSEPR model.

Hybridization of atomic orbitals