# Does solid manganese reacts with atmospheric air when heated?

As discussed in my answer, manganese is not particularly reactive to air. The surface of manganese lumps oxidize to a minor extent but when it is finely divided, it becomes pyrophoric and burns in air. It tends to form the oxide $$\ce{Mn3O4}$$ and the nitride $$\ce{Mn3N2}$$. It was fine until I came across this statement from Concise Inorganic Chemistry by J.D.LEE:

The finely divided metal is pyrophoric in air, but the massive metal does not react until heated. When strongly heated, the massive metal reacts with many non-metals such as $$\ce{O2, N2, Cl2}$$ and $$\ce{F2}$$, forming $$\ce{Mn3O4, Mn3N2, MnCl2}$$ and a mixture of $$\ce{MnF2}$$ and $$\ce{MnF3}$$

I was under the impression that manganese is relatively inert and normally won't oxidize unless it is powdered but the book says otherwise. Nowhere, I found any source backing the statement.

Question: Does solid manganese reacts with atmospheric air when heated (if so, at what temparture)?

• If something is pyrophoric when powdered, it does react when in bulk too, but may react slowly, in limited extent and just in thin surface layer. Like Al, or Fe(in dry air). Jun 18 at 5:46
• The tricky part is, what exactly do you mean by "reacts", kinetic-wise. Jun 18 at 6:01