P₄(s) + 5O₂(g) → P₄O₁₀(s)

Here's what it represents:

* P₄(s): Phosphorus exists as a tetratomic molecule (P₄) in its solid state.

* O₂(g): Oxygen is a diatomic molecule in its gaseous state.

* P₄O₁₀(s): The product of burning phosphorus in air is phosphorus pentoxide, which is a solid.

This equation shows that one molecule of tetraphosphorus (P₄) reacts with five molecules of oxygen (O₂) to produce one molecule of phosphorus pentoxide (P₄O₁₀).