Question

The molecule that deviates from octet rule is:

• A. $NaCl$
• B. $BeC{l}_2$
• C. $MgO$
• D. $N{H}_3$

Answer 1

The correct option is B $BeC{l}_2$

Be has electronic configuration${1s}^2{2s}^2$. The two valence electrons give Be +2 oxidation state and ability to form two covalent bonds.

Due to octet rule atoms tend to seek a valence of 8 but Be tries to achieve a coordination number of 4 as the two covalent bonds fill half of this octet.

Hence, the correct option is $\text{B}$