## Octet Exceptions

$FC=V-(L+\frac{S}{2})$

Matia Kim 1B
Posts: 60
Joined: Fri Apr 06, 2018 11:03 am

### Octet Exceptions

With elements with exceptions in their classification like Copper and Chromium, does that change the number of valence electrons they produce?

Nicole Elhosni 2I
Posts: 62
Joined: Fri Sep 28, 2018 12:28 am

### Re: Octet Exceptions

Both copper and chromium have 1 electron in their valence shell, because both have 4s^1 as their final orbital in their electron configuration, Cr [Ar] 3d^5 4s^1, Cu [Ar] 3d^10 4^1. I don't think knowing their valence electrons is as important as elements in group 1,2, 13-17 anyway because Cr and Cu are transition metals so they can form more than one cation.

Sean Reyes 1J
Posts: 67
Joined: Fri Sep 28, 2018 12:24 am

### Re: Octet Exceptions

The exceptions that copper and chromium have in their d-orbitals are different than having an expanded octet (which exist when n>2). Because these elements exist in the transition metals, they have really weird rules as to how their valence electrons work.
But yes, copper and chromium would have one valence electron as their outermost shell (n=4) has only one electron in it.

Posts: 62
Joined: Fri Sep 28, 2018 12:23 am

### Re: Octet Exceptions

Since the exceptions would allow for the elements to fill up their d orbital it would affect the number in the valence shell.

Soumya Ravichandran 4H
Posts: 62
Joined: Fri Sep 28, 2018 12:19 am

### Re: Octet Exceptions

Yes, it does. We covered in class these two elements as exceptions but also when we did electron configurations of ions, such as Cu+ we only removed the 4s1 electron, which proves that valence electrons are being affected.