Explain the bond formation in $BeCl_{2}$ and explain why $BeCl_{2}$ is linear.

(N/A) In $BeCl_{2}$,the ground state electronic configuration of $Be$ is $[He] 2s^{2}$.
To form two bonds,$Be$ undergoes excitation to $Be^{*}$ with configuration $[He] 2s^{1} 2p^{1}$.
One $2s$ and one $2p$ orbital of the excited $Be$ atom undergo $sp$ hybridization to form two equivalent $sp$ hybrid orbitals.
These two $sp$ hybrid orbitals are oriented in opposite directions to minimize repulsion,resulting in a bond angle of $180^{\circ}$.
Each $sp$ hybrid orbital of $Be$ overlaps axially with the half-filled $3p_{z}$ orbital of a chlorine $(Cl)$ atom,forming two $Be-Cl$ $\sigma$ bonds.
Due to this linear arrangement of the two $sp$ hybrid orbitals,the $BeCl_{2}$ molecule adopts a linear geometry.