Question

Which pair of elements listed below could be central atoms that can exceed an octet of valence electrons?

Answer 1

Atoms in period three and beyond can exceed an octet of valence electrons due to the presence of empty d orbitals. Molecules like PCl5 and SF6 are examples of compounds with central atoms that have expanded octets.

Step-by-step explanation:

Atoms in period three and beyond can exceed an octet of valence electrons because they have empty d orbitals in addition to the valence s and p orbitals. This allows them to share more than four pairs of electrons and have expanded octets. For example, molecules like PCl5 and SF6 have central atoms that exceed an octet of valence electrons.