Name: Phosphorus Symbol: P Atomic Number: 15 Atomic Weight: 30.9738(2) Density: 1.82 g/cc Melting Point: 44.15 C Boiling Point: 279.85 C Electron Configuration: 1s2 2s2 2p6 3s2 3p3 Chemical Group: Non-Metals Detailed Technical Data The data on this page is more precise and in some cases more up-to-date than the data engraved on the wooden tiles. But as always, never believe one source if the number really matters. Density, melting point and boiling point data is particularly variable and uncertain. Atomic weight data for stable elements from IUPAC 1999 Official Publication. (Uncertainty in parentheses.)