You're asking about the oxidation number of Mn₂. It's important to note that Mn₂ doesn't exist as a stable, independent entity.

Here's why:

* Manganese (Mn) is a transition metal, and it typically exists in various oxidation states. To determine its oxidation number, we need to look at the compound it's part of.

* Oxidation numbers are assigned to atoms in a compound based on a set of rules.

For example:

* In MnO₂ (Manganese Dioxide), the oxidation number of Mn is +4.

* In KMnO₄ (Potassium Permanganate), the oxidation number of Mn is +7.

Therefore, to figure out the oxidation number of manganese (Mn), you need to tell me the compound it's in.