Question

Which of the following has an expanded octet?

• A. NH\(_3\)
• B. H\(_2\)SO\(_4\)
• C. SF\(_4\)
• D. BeCl\(_2\)

Hint:

For elements in the third period and beyond, look for those that can have an expanded octet, as they have available d-orbitals to accommodate extra electrons.

Answer 1

The Correct Option is C

An expanded octet occurs when an atom has more than 8 electrons in its valence shell. This typically happens for atoms in the third period or higher, which have available d-orbitals that can accommodate more than 8 electrons. - NH\(_3\) (Ammonia): The nitrogen atom in NH₃ follows the octet rule with 8 electrons in its valence shell. - H\(_2\)SO\(_4\) (Sulfuric acid): The sulfur atom in H₂SO₄ does not have an expanded octet. It follows the octet rule with 8 electrons in its valence shell. - SF\(_4\) (Sulfur tetrafluoride): The sulfur atom in SF₄ has an expanded octet, with 10 electrons in its valence shell. This is possible because sulfur is in period 3 and can use d-orbitals to accommodate more electrons. - BeCl\(_2\) (Beryllium chloride): Beryllium typically does not expand its octet and follows the octet rule, having only 4 electrons in its valence shell. Thus, SF₄ is the correct answer as it has an expanded octet.