Also phosphorous is the ion (PO3)3-.
Formula: P4
The chemical symbol (not formula) of phosphorous is P; the chemical symbol (not formula) of chlorine is Cl.
Formula: PCl3
You think probable to the unstable compound P4S2.
Formula: P2O3
The formula (symbol) for aluminum is Al. The symbol for phosphorous is P. The formula for aluminum combined with phosphorous is AlP (aluminum phosphide).
P4Se3
Phosphorous Hydride = PH3
Phosphorous Trioxide
PCl3
Phosphorus pentachloride is a chemical compound with the formula PCl5.
Phosphorous Acid, A balancing of a phosphite (a salt of phosphorous acid) and three hydrogen's to achieve net neutrality.