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In the BeCl 2 molecule chemical bonds are formed as a result of overlapping of

two hybrid orbitals of the Beryllium atom and orbitals of Chlorine atoms. This

type of hybridization is called sp-hybridization. Let us consider the scheme of

overlapping orbitals in the BeCl 2 molecule.

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Electronic formula of Beryllium is 4Be ... 2s . The electrons distribution of the
external energy level in quantum cells is as follows

0
0
0
2 2p х 2p y 2p z
2s

In this state, which is called the ground state, Beryllium valence is zero, that is
there are no unpaired electrons capable of forming chemical bonds. In compounds

Beryllium is divalent due to the possibility of the decomposition of s-electrons of

the external energy level and their placing on p-orbitals

0
0
1
1 2p х 2p y 2p z
2s

The decomposition occurs due to the energy released by the chemical
interaction of Beryllium, its atom turns into the so-called "excited state".

Consequently, the excitation of atoms is the decomposition of electrons within a

single energy level. It is established that the chemical bonds formed by these two

electrons in the corresponding orbits are equivalent. This means that the alignment

of the wave functions of the 2s- and 2p-orbitals occurs. Instead of the individual s-

and p-orbitals there are two identical orbitals - hybrid orbitals, which are in the

form of asymmetric eights and are located at an angle of 180 ° to one another. The

sp-hybridization process is shown below schematically

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