Question

Which element is MOST likely to violate the Octet Rule?

A. F

B. S

C. As

D. None of these elements is likely to violate octet rule

E. Two or more of these likely violate octet rule

Explain in sufficient detail (minimum 40-50 words) which elements are likely to violate the octet rule, and why. Also explain which nonmetals nearly always obey the octet rule, and why.

Answer 1

Ans : B) S

According to the octet rule , the central atom of the molecule in a compound must have 8 electrons to attain stability. But we see some elements are likely to violate this octet rule and form expanded octet such as : sulfur , phosphorus , chlorine etc.

These elements are the ones that are found in right side of the period 3 in the modern periodic table. This happens because they have empty d orbitals in their shells , so they can accept electrons in their empty orbitals . The elements which do not have much empty orbitals such as the ones present in s and p orbitals of modern periodic table do not violate the octet rule.

For example : hydrogen , helium , lithium etc.