## Radicals, which atoms lacks electron?

Anna Yakura 2F
Posts: 130
Joined: Wed Sep 30, 2020 9:46 pm

### Radicals, which atoms lacks electron?

Hello, I asked this question some time ago but I never got a clear answer so I thought I'd ask again.
With a radical, how do you know which atom has less than 8 electrons?

Melody Haratian 2J
Posts: 119
Joined: Wed Sep 30, 2020 9:48 pm
Been upvoted: 1 time

### Re: Radicals, which atoms lacks electron?

Hello!
For a radical, if an atom has an unpaired valence electron (or 7 electrons instead of 8) then it is a radical. You can tell if the valence electron is unpaired if one of its electrons is alone. So if an atom has or is sharing ( through covalent bonds) 6 electrons and has one additional unpaired electron, it will be a radical since one of its electrons won’t be paired while all of its other electrons are paired. This makes the atom very reactive.
I hope this helps!

clairehathaway 2J
Posts: 106
Joined: Wed Sep 30, 2020 9:38 pm

### Re: Radicals, which atoms lacks electron?

What about in something like ClO? If you were asked to draw that you know that there are only 13 electrons available to distribute between the two but how do you decide which one will get the lone electron? Does it have to do with electronegativity or electron affinity?

Ariana Flores 3F
Posts: 48
Joined: Thu Sep 19, 2019 12:16 am

### Re: Radicals, which atoms lacks electron?

I think that the only exceptions we need to know to the Octet rule are:

More than an octet:
Chromium and Copper

Chromium: we expect a configuration including $3d^{4}$if we look at the PT, however, the observed configuration is actually [Ne]$3s^{2}$$3p^{6}$$3d^{5}$$4s^{1}$
Copper: we expect to see $3d^{9}$ when we use the PT, however, the configuration is actually
[Ne]$3s^{2}$$3p^{6}$$3d^{10}$$4s^{1}$

Less than an octet:
First four elements [H, He, Li, Be] (They're full shells add up to 2 electrons or 4 electrons) This one is easier to remember because it just means these elements only have s-state orbitals, so they're valence electrons will never add up to more than 4.

Acid-Base Interactions:
Involving B or Al

* The ability to have an expanded octet comes from an element that has d-state characteristics. Meaning, as soon as our electron configuration includes "d", the octet rule no longer applies. This is because the 8 in octet comes from the possibility of 2 electrons (spin up, spin down) in each orbital. (Remember Lewis structures only include valence electrons) There is 1 orbital (2 possible electrons) in the s-state and there are 3 orbitals (6 possible electrons) in the p orbital for a total of 8 electrons to make an octet.

With all that, to answer your question, I don't think we have to know anything besides a radical has an unpaired electron and it's very reactive. I don't think we have any rules or guidelines to determine what molecules can form radicals. I might be totally wrong too maybe we do know how to figure this out, (my bad) but I hope that helps and made sense!