Is an oxygen atom an oxygen radical ? Do they mean the same thing

When I draw the cross and dot diagram of an oxygen atom, I group the 6 valence electrons into 3 pairs of 2 electrons.

However, the electronic configuration of oxygen is 1s2 2s2 2p4

Leaving 2 electrons in the 2p orbitals unpaired.


So why in the dot and cross diagram all electrons are drawn as ''paired '' when in actual fact there are 2 unpaired electrons ?

Thanks so much!

The term "radical" has meant different things at different times. At one time "radical" referred to a group of atoms with a net charge, a polyatomic ion. Today, the term "radical" refers to a "free radical". A free radical is an atom or compound or even an ion with one or more unpaired electrons. A single oxygen atom has two unpaired electrons, at least, according to the Lewis diagram, and would be a free radical. The interesting thing is that an oxygen molecule, O2, is also a free radical and has two unpaired electrons. This explains why O2 is paramagnetic. Unfortunately, the commonly drawn Lewis diagram does not predict the two unpaired electrons.

=========== Follow up ============

When you draw the Lewis diagram of a single oxygen atom, you should get two pairs of electrons and two electrons which are unpaired. It should look like this: http://www.angelfire.com/theforce2/chem/…

When I introduce my students to Lewis structures, we start with the individual atoms. I tell them to first determine the number of valence electrons and then to place one dot on each of four sides and then to start pairing them up. It is a sort of Hund's rule for Lewis structures. Using this approach you will get two unpaired electrons for an oxygen atom.