Geometry of Diatomic Molecules

graphic of a diatomic molecule

ThoughtCo / Ben Mills

Many molecules are diatomic, meaning they consist of two elements. Diatomic molecules all have the same shape or geometry. Here's a look at what this geometry is and why all diatomic molecules are the same in this regard.

All diatomic molecules are linear. It doesn't matter whether they are diatomic elements or heteronuclear diatomic molecules.

Diatomic molecules have to assume linear geometry because the only way to connect two points is with a line. The nuclei of the atoms are repelled by each other, so they tend to push each other away, even as the electrons are being shared. There is characteristic vibration in the resulting bond, which can be observed using lab techniques, such as spectroscopy.