The Pi bond is again, the name of the shape and is found as an electron cloud above and below the sigma orbital. These unhybridized p electrons can combine with another p electron to form a Pi bond. If only three orbitals combine, there is an sp2 hybrid (leaving one electron in a p orbital) and if only two orbitals combine, an sp hybrid (leaving two electrons in two p orbitals). As they are equal, the electrons rearrange themselves to move into each empty orbital and it is called an sp3 hybrid. When carbon reacts, the s orbital gains a bit of energy, the p orbitals lose a bit of energy and they all become equal. Remember, there are three p orbitals so in the ground state, there is only two electrons in two separate p orbitals. Carbon, in the ground state has the arrangement 1s2 2s2 2p2. Sp3 hybrid orbitals are formed when the s and p orbitals in carbon combine to become equal. Horn (CC-BY-SA 3.0 ), via Wikimedia Commons The shape looks: Source: ZooFari Raster: Anselm H. Where an sp1, 2 or 3 hybrid combines with another sp1, 2 or 3 or an s orbital or a p orbital I always tell my students that all this is doing is describing the shape of the bond.Īn s and p orbital combine where the p is sideways on So I guess you could argue that they are at least close together. Hybrid orbitals is an AHL concept, covered in section 14.2, shapes of molecules are found in 4.3 and 14.1 and hybridization in 14.2 as well. Where do I start? Well, the three above concepts (Sigma & Pi, shape and hybrid orbitals) are, in my opinion connected … Except they are not directly connected in the syllabus. It wasn’t covered when I did my biochemistry degree and I only felt like I really understood things until I started teaching about the concepts … so I really hope this blog post helps your understanding of things. I was really confused with this information when I was a student.

Sigma bond shape