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Element: Praseodymium

General data

Element namePraseodymium
Chemical symbolPr
Atomic number Z59
Year discovered1885
Standard state (25°C)Solid
CategoryLanthanide
Blockf
Atomic mass140.91
CPK color#D9FFC7

Physical properties

Melting point1204 K (931 °C)
Boiling point3793 K (3520 °C)
Density6.77 g/cm³

Energy properties

First ionization energy5.464 eV
Electron affinityno data

Atomic structure

Protons59 (Atomic number)
Neutrons (Pr-141, most abundant isotope)82
Electrons59
Electron configuration[Xe] 6s² 4f³
Oxidation states+3
Electronegativity (Pauling)1.13
Atomic radius (van der Waals)239 pm

Ionization energies - NIST ASD (59 states)

StateChargeIoniz. energy (eV)Type
Pr I0+5.4702 ± 0.0004semi-empirical
Pr II1+10.631 ± 0.02semi-empirical
Pr III2+21.6237 ± 0.0025measured
Pr IV3+38.981 ± 0.025semi-empirical
Pr V4+57.53 ± 0.05semi-empirical
Pr VI5+82 ± 4calculated
Pr VII6+97 ± 5calculated
Pr VIII7+112 ± 6calculated
Pr IX8+131 ± 7calculated
Pr X9+148 ± 7calculated
Pr XI10+162 ± 2.4calculated
Pr XII11+196 ± 2.5calculated
Pr XIII12+217.02 ± 0.12semi-empirical
Pr XIV13+350 ± 3calculated
Pr XV14+378 ± 3calculated
Pr XVI15+412 ± 3calculated
Pr XVII16+445 ± 3calculated
Pr XVIII17+478 ± 3calculated
Pr XIX18+516 ± 3calculated
Pr XX19+554 ± 4calculated
Pr XXI20+590 ± 4calculated
Pr XXII21+627 ± 4calculated
Pr XXIII22+663 ± 4calculated
Pr XXIV23+803 ± 4calculated
Pr XXV24+840 ± 4calculated
Pr XXVI25+880 ± 4calculated
Pr XXVII26+920 ± 4calculated
Pr XXVIII27+985 ± 4calculated
Pr XXIX28+1028 ± 4calculated
Pr XXX29+1124 ± 4calculated
Pr XXXI30+1169.9 ± 0.6semi-empirical
Pr XXXII31+2019 ± 4calculated
Pr XXXIII32+2108 ± 4calculated
Pr XXXIV33+2202 ± 5calculated
Pr XXXV34+2304 ± 5calculated
Pr XXXVI35+2400 ± 5calculated
Pr XXXVII36+2501 ± 5calculated
Pr XXXVIII37+2628 ± 4calculated
Pr XXXIX38+2729 ± 4calculated
Pr XL39+2838 ± 4calculated
Pr XLI40+2941 ± 4calculated
Pr XLII41+3227 ± 4calculated
Pr XLIII42+3319 ± 4calculated
Pr XLIV43+3419 ± 4calculated
Pr XLV44+3512 ± 4calculated
Pr XLVI45+3729 ± 4calculated
Pr XLVII46+3832 ± 4calculated
Pr XLVIII47+4030 ± 4calculated
Pr XLIX48+4130 ± 4calculated
Pr L49+9378 ± 4calculated
Pr LI50+9632 ± 4calculated
Pr LII51+9913 ± 4calculated
Pr LIII52+10175 ± 4calculated
Pr LIV53+10959 ± 5calculated
Pr LV54+11262 ± 5calculated
Pr LVI55+11641 ± 5calculated
Pr LVII56+11895.89 ± 0.06calculated
Pr LVIII57+48571.71 ± 0.05calculated
Pr LIX58+49722.44 ± 0.04calculated

Value type as given by NIST ASD: measured - from evaluated experimental data; calculated - from ab initio calculations (mostly highly ionised atoms that have not been measured; for the simplest ones, e.g. H I, the calculation is more accurate than measurement); semi-empirical - from interpolation, extrapolation or another semi-empirical method.

Photos

Photo of the element: Praseodymium (Pr)
© images-of-elements.com (CC BY 3.0)

Isotopes (39)

ANHalf-lifeDecay
Pr-1216210 msp
Pr-124651.2 sEC/β⁺
Pr-125663.3 sEC/β⁺
Pr-126673.12 sEC/β⁺
Pr-127684.2 sEC/β⁺
Pr-128692.8 sEC/β⁺
Pr-1297031 sEC/β⁺
Pr-1307140.0 sEC/β⁺
Pr-131721.49 minEC/β⁺
Pr-132731.6 minEC/β⁺
Pr-133746.5 minEC/β⁺
Pr-1347517 minEC/β⁺
Pr-1357625.4 minEC/β⁺
Pr-1367713.1 minEC/β⁺
Pr-137781.28 hEC/β⁺
Pr-138791.45 minEC/β⁺
Pr-139804.41 hEC/β⁺
Pr-140813.39 minEC/β⁺
Pr-14182stable-
Pr-1428319.12 hβ⁻
Pr-1438413.57 dβ⁻
Pr-1448517.28 minβ⁻
Pr-145865.982 hβ⁻
Pr-1468724.09 minβ⁻
Pr-1478813.35 minβ⁻
Pr-148892.29 minβ⁻
Pr-149902.26 minβ⁻
Pr-150916.19 sβ⁻
Pr-1519218.90 sβ⁻
Pr-152933.57 sβ⁻
Pr-153944.29 sβ⁻
Pr-154952.30 sβ⁻
Pr-155961.47 sβ⁻
Pr-15697444 msβ⁻
Pr-15798300 msβ⁻
Pr-15899181 msβ⁻
Pr-159100130 msβ⁻
Pr-160101170 msβ⁻
Pr-161102unknownβ⁻

Data sources

More about the data sources