Covalent compounds of beryllium and boron are the most common exceptions, though compounds with odd numbers of electrons also violate this rule and are therefore generally unstable.
Many compounds that do not follow it dimerize, including nitrogen oxide. Exceptions to it include many compounds in Group IIIA, but Group IIA does not feature exceptions because of lower ionization energies and larger radii. Covalent compounds of beryllium and boron are the most common exceptions, though compounds with odd numbers of electrons also violate this rule and are therefore generally unstable. FTP, identify this chemical rule, which states that compounds seek to achieve noble gas configurations by obtaining eight valence shell electrons.
Many compounds that do not follow it dimerize, including nitrogen oxide.
{octet} rule  .