Question

direct combination reaction between Phosphorus and a neutral gas

Answer 1

hey mate here is ur ans

we take the neutral gas as oxygen
we get phosphorus pentoxide

P4+5O2---->2P2O5


hope it helps you frnd

Answer 2

Oxygen gas is generally considered as the natural gas. The chemical formula of natural gas is $O_2$ gas. It is molecule composed of O atoms which is a non-metal. It is mainly involved in the formation of oxides. The reaction of oxygen with other non-metal forms oxides.  

The balance chemical reaction of phosphorus with oxygen is as given below:

$\mathbf{P}+\mathbf{O}_{2} \rightarrow \mathrm{P}_{2} \mathrm{O}_{5}$

It forms the phosphorus pentoxide which is an oxide of phosphorus element.