# How do you predict the hybridisation of an atom in a molecule?

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For example, the #N# atom in Pyridine is #sp^2# hybridised. But how do you find that?

For example, the

##### 1 Answer

You look at the number of electron groups. There's more to it than that, but at a basic level...

*The number of electron groups equals the number of orbitals used to construct the hybridized orbitals.*

You might find it useful to look over this answer as well.

*DISCLAIMER: Long answer!*

**PYRIDINE HYBRIDIZATION**

In pyridine, what you have on the *major resonance structure* of pyridine has

**one**connected to a carbon via a single bond**one**connected to a carbon via a double bond**one**that is a lone pair of electrons

With **three** electron groups, you have the **three**

**ORBITAL PERSPECTIVE OF PYRIDINE**

Actually, the

**two hybridized**#sp^2# atomic orbital lobes partially occupied with one electron (both used to#sigma# *bond*).**one unhybridized**#2p_z# atomic orbital lobe partially occupied with one electron (used to#pi# bond within the ring), perpendicular to the ring. This is not included in the counting of electron groups, because it isn't hybridized.**one hybridized nonbonding**#sp^2# atomic orbital lobe (the third one of three) that holds the*lone pair*, parallel to the ring.

Let's fill in the missing

The *diagonal* (*off* the Cartesian coordinate axes) manner in **2** dimensions (on the

The **not compatible** with a

So, they, along with the **three**

The hybridization must occur to make *diagonal* bonds that are **all identical in energy and look**.

The