CAS: 7440-10-0 EC No: 231-120-3 MDL No: MFCD00011174 UN No: UN3089; Haz Class: 4.1; Packing Group: II Powder Molecular Formula: Pr MW: 140.91 Melting Point: 931° Boiling Point: 3520° Density (g/mL): 6.71