1.0 2015-02-28 11:54:08 UTC 2025-11-19 03:00:12 UTC FDB030050 Praseodymium Praseodymium, also known as 59pr or praseodimio, is a member of the class of compounds known as homogeneous lanthanide compounds. Homogeneous lanthanide compounds are inorganic compounds containing only metal atoms, with the largest atom being a lanthanide atom. Praseodymium can be found in dill, red beetroot, romaine lettuce, and spinach, which makes praseodymium a potential biomarker for the consumption of these food products. Praseodymium always occurs naturally together with the other rare-earth metals. It is the fourth most common rare-earth element, making up 9.1 parts per million of the Earth's crust, an abundance similar to that of boron. In 1841, Swedish chemist Carl Gustav Mosander extracted a rare-earth oxide residue he called didymium from a residue he called "lanthana", in turn separated from cerium salts. In 1885, the Austrian chemist Baron Carl Auer von Welsbach separated didymium into two elements that gave salts of different colours, which he named praseodymium and neodymium. The name praseodymium comes from the Greek prasinos (πράσινος), meaning "green", and didymos (δίδυμος), "twin" . Pr 140.9077 140.90766 praseodymium praseodymium 7440-10-0 [Pr] InChI=1S/Pr PUDIUYLPXJFUGB-UHFFFAOYSA-N belongs to the class of inorganic compounds known as homogeneous lanthanide compounds. These are inorganic compounds containing only metal atoms, with the largest atom being a lanthanide atom. Homogeneous lanthanide compounds Inorganic compounds Homogeneous metal compounds Homogeneous lanthanide compounds Homogeneous lanthanide f-block element atom lanthanoid atom logp 0 ChemAxon iupac praseodymium ChemAxon average_mass 140.9077 ChemAxon mono_mass 140.90766 ChemAxon smiles [Pr] ChemAxon formula Pr ChemAxon inchi InChI=1S/Pr ChemAxon inchikey PUDIUYLPXJFUGB-UHFFFAOYSA-N ChemAxon polar_surface_area 0 ChemAxon refractivity 0 ChemAxon polarizability 1.78 ChemAxon rotatable_bond_count 0 ChemAxon acceptor_count 0 ChemAxon donor_count 0 ChemAxon physiological_charge 0 ChemAxon formal_charge 0 ChemAxon Dill Type 1 specific Anethum graveolens 40922 0.00004 0.00004 0.00004 mg/100 g Red beetroot Type 1 specific Beta vulgaris var. rubra 0.0001 0.0001 0.0001 mg/100 g Romaine lettuce Type 1 specific Lactuca sativa L. var. longifolia 0.0 0.0 0.0 mg/100 g Spinach Type 1 specific Spinacia oleracea 3562 0.0003 0.0004 0.0002 mg/100 g