Phosphorus reacts with chlorine to form a phosphorus chloride compound.
A sample of this phosphorus chloride contains 3.1 g of phosphorus atoms and 10.65 g of chlorine atoms.
Calculate the empirical formula of this sample of phosphorus chloride. (Relative atomic masses, ArA_{\text{r}}Ar: P=31\text{P} = 31P=31, Cl=35.5\text{Cl} = 35.5Cl=35.5)