Name: Molybdenum Symbol: Mo Atomic Number: 42 Atomic Weight: 95.94(1) Density: 10.22 g/cc Melting Point: 2616.85 C Boiling Point: 4611.85 C Electron Configuration: 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d5 5s1 Chemical Group: Transition 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.) Special notes for this element from IUPAC publication: Geological specimens are known in which the element has an isotopic composition outside the limits for normal material. The difference between the atomic weight of the element in such specimens and that given in the Table may exceed the stated uncertainty.