PO₄³⁻ is a stable ion of phosphorous. Using Lewis structures, explain why NO₄³⁻ does not exist even though N and P are from the same group.

Which oxygen species does not violate the octet rule?

a) hydroxide (OH^–)
b) hydroxyl (OH•)
c) superoxide (O₂•^–)

Identify the compound or ion that is an exception to the octet rule: ICl, BeCl₂, NCl₃.

Free radicals are defined as chemical species that contain an odd number of electrons. Radicals are unstable species and react readily with other molecules. Draw a Lewis dot structure for the nitric oxide radical (NO).