Template:Infobox praseodymium

Praseodymium, ₅₉Pr
Praseodymium
Pronunciation	/ˌpreɪzioʊˈdɪmiəm/ (PRAY-zee-oh-DIM-ee-əm)
Appearance	grayish white
Standard atomic weight Ar, std(Pr)	140.90766(1)
Praseodymium in the periodic cairt
	cerium ← praseodymium → neodymium
Atomic nummer (Z)	59
Group	group n/a
Period	period 6
Block	f-block
Element category	Lanthanide
Electron confeeguration	[Xe] 4f3 6s2
Electrons per shell	2, 8, 18, 21, 8, 2
Pheesical properties
Phase at STP	solit
Meltin pynt	1208 K (935 °C, 1715 °F)
Bylin pynt	3793 K (3520 °C, 6368 °F)
Density (near r.t.)	6.77 g/cm3
when liquid (at m.p.)	6.50 g/cm3
Heat o fusion	6.89 kJ/mol
Heat o vapourisation	331 kJ/mol
Molar heat capacity	27.20 J/(mol·K)
Atomic properties
Oxidation states	0, +1, +2, +3, +4, +5 (a mildly basic oxide)
Electronegativity	Pauling scale: 1.13
Atomic radius	empirical: 182 pm
Covalent radius	203±7 pm
	Colour lines in a spectral rangeSpectral lines o praseodymium
Ither properties
Naitural occurrence	primordial
Creestal structur	hexagonal
Speed o soond thin rod	2280 m/s (at 20 °C)
Thermal expansion	(r.t.) (α, poly) 6.7 µm/(m·K)
Thermal conductivity	12.5 W/(m·K)
Electrical resistivity	(r.t.) (α, poly); 0.700 µ Ω·m
Magnetic orderin	paramagnetic
Young's modulus	(α form) 37.3 GPa
Shear modulus	(α form) 14.8 GPa
Bulk modulus	(α form) 28.8 GPa
Poisson ratio	(α form) 0.281
Vickers haurdness	400 MPa
Brinell haurdness	481 MPa
CAS Nummer	7440-10-0
History
Diskivery	Carl Auer von Welsbach (1885)
Main isotopes o praseodymium
ε	142Ce
	Decay modes in parentheses hae been predictit, but hae nae yet been observed
	view; talk; edit; \| references

style="text-align:left"\| data m.p. cat v
	in	calc from C	diff	report	ref
C	935	—	—
K	1208	1208	0
F	1715	1715	0
WD	1208 !1208 kelvin
input	C: 935, K: 1208, F: 1715
comment

style="text-align:left"\| data b.p. cat v
	in	calc from C	diff	report	ref
C	3520	—	—
K	3793	3790	3	delta
F	6368	6370	-2	delta
WD	3403 !3403 kelvin
input	C: 3520, K: 3793, F: 6368
comment

References

↑ "praseodymium". Oxford English Dictionary (3rd ed.). Oxford University Press. September 2005. (Subscription or UK public leebrar membership required.)
↑ Meija, Juris; et al. (2016). "Atomic weights of the elements 2013 (IUPAC Technical Report)". Pure and Applied Chemistry. 88 (3): 265–91. doi:10.1515/pac-2015-0305.
↑ Yttrium and all lanthanides except Ce, Pm, Eu, Tm, Yb have been observed in the oxidation state 0 in bis(1,3,5-tri-t-butylbenzene) complexes, see Cloke, F. Geoffrey N. (1993). "Zero Oxidation State Compounds of Scandium, Yttrium, and the Lanthanides". Chem. Soc. Rev. 22: 17–24. doi:10.1039/CS9932200017.
↑ Chen, Xin; et al. (13 December 2019). "Lanthanides with Unusually Low Oxidation States in the PrB^3– and PrB^4– Boride Clusters". Inorganic Chemistry. 58 (1): 411–418. doi:10.1021/acs.inorgchem.8b02572. PMID 30543295.
↑ M. Jackson "Magnetism of Rare Earth" The IRM quarterly col. 10, No. 3, p. 1, 2000

[1] "praseodymium". Oxford English Dictionary (3rd ed.). Oxford University Press. September 2005. (Subscription or UK public leebrar membership required.)

[CIAAW2013-2] Meija, Juris; et al. (2016). "Atomic weights of the elements 2013 (IUPAC Technical Report)". Pure and Applied Chemistry. 88 (3): 265–91. doi:10.1515/pac-2015-0305.

[Cloke1993-3] Yttrium and all lanthanides except Ce, Pm, Eu, Tm, Yb have been observed in the oxidation state 0 in bis(1,3,5-tri-t-butylbenzene) complexes, see Cloke, F. Geoffrey N. (1993). "Zero Oxidation State Compounds of Scandium, Yttrium, and the Lanthanides". Chem. Soc. Rev. 22: 17–24. doi:10.1039/CS9932200017.

[4] Chen, Xin; et al. (13 December 2019). "Lanthanides with Unusually Low Oxidation States in the PrB^3– and PrB^4– Boride Clusters". Inorganic Chemistry. 58 (1): 411–418. doi:10.1021/acs.inorgchem.8b02572. PMID 30543295.

[jackson-5] M. Jackson "Magnetism of Rare Earth" The IRM quarterly col. 10, No. 3, p. 1, 2000

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