Will two isolated atoms form a bond by themselves?

[Ivan Bevanda E]

For example: If I isolated (in a perfect vacuum), one Magnesium atom and one Oxygen atom, and they are close to each other, will they make a bond by themselves, with no outside energy? Does this work with any combinable pair of atoms, and what other pairs of atoms would make a bond by themselves, if any?

Thank you for your replies, Ivan.

 

[DrClaude]

First, there is a barrier to the reaction: some initial energy input is necessary. If there is no additional energy (like kinetic energy), then most probably nothing will happen. Second, there needs to be a mechanism by which the binding energy can be removed. Unless this can be done here by emission of a photon, even if a bond can be formed temporarily, it will not be stable and the molecule will decay back to individual atoms.