## Sigma and Pi Bonds

$sp, sp^{2}, sp^{3}, dsp^{3}, d^{2}sp^{3}$

Megan FitzPatrick 1C
Posts: 17
Joined: Fri Sep 25, 2015 3:00 am

### Sigma and Pi Bonds

When you are going about finding the number of sigma and pi bonds in a molecule, do you always have to draw the Lewis structure for that particular molecule to determine which elements have single (sigma), double (sigma+1pi), and triple bonds (sigma+2pi bonds)? Also, I read online that only period two elements form pi bonds. Is this correct?

Saira Shahid 3K
Posts: 48
Joined: Fri Sep 25, 2015 3:00 am

### Re: Sigma and Pi Bonds

Sigma and pi bonds are made when two orbitals overlap. Sigma bonds are made when two hybridized orbitals overlap, and pi bonds are always made from two P-orbitals.

A single bond is a sigma bond.
A double bond is one sigma and one pi bond.
A triple bond is one sigma and two pi bonds.

I always draw the Lewis structure to find the sigma and pi bonds, and I'm not sure if there's another way to find them.

Hannah Markovic 3C
Posts: 32
Joined: Fri Sep 25, 2015 3:00 am

### Re: Sigma and Pi Bonds

Yes, I agree that you should draw the lewis structure first in order to find the number of sigma and pi bonds. Also, it's correct that only period 2 and higher elements can form pi bonds because hydrogen and helium will not form double bonds since their "octet" (2 electrons) is satisfied with just one bond for both :)

Cynthia De Luna 4I
Posts: 5
Joined: Fri Sep 25, 2015 3:00 am

### Re: Sigma and Pi Bonds

Yeah, so far the best way that I've found for figuring out sigma and pie bonds is to draw out the Lewis Structure. I saw a video on youtube that had a different method but it was a bit complicated.

Sakiko_Shida_4E
Posts: 8
Joined: Fri Sep 25, 2015 3:00 am

### Re: Sigma and Pi Bonds

Yes, it is correct that only elements in period two or higher form pi bonds because H and He in period 1 of the periodic table can only share one pair of electrons between the atoms and do not form double or triple bonds.