Exceptions to octet rule

[annikaying]

Which elements can break the octet rule when forming lewis dot structures and is it likely or just when necessary?

[rabiasumar2E]

In lecture he said that atoms in period 3 or higher can accommodate additional electrons because they have d-orbitals, allowing them room to do so. I think breaking the octet rule is done when trying to draw the lewis structure most accurately with the lowest energy or sometimes just to get the right amount of electrons to show. It just depends on the situation.

[805291863]

The other exception to the octet rule is atoms that do not need 8 electrons to be stable. H and Li only want 2 electrons, and B can be stable with 6 electrons.

[005162520]

Another exception include radicals in which electrons have incomplete octets because their electrons have unpaired spins such methyl radical.

[Ruby Richter 2L]

What would be another example of a radical having an incomplete octet because of unpaired spins?