Template:Infobox neptunium

Neptunium, ₉₃Np
Neptunium
Pronunciation	/nɛpˈtjuːniəm/ (nep-TEW-nee-əm)
Appearance	sillery metallic
Mass number	[237]
Neptunium in the periodic cairt
	uranium ← neptunium → plutonium
Atomic nummer (Z)	93
Group	group n/a
Period	period 7
Block	f-block
Element category	Actinide
Electron confeeguration	[Rn] 5f4 6d1 7s2
Electrons per shell	2, 8, 18, 32, 22, 9, 2
Pheesical properties
Phase at STP	solit
Meltin pynt	912±3 K (639±3 °C, 1182±5 °F)
Bylin pynt	4447 K (4174 °C, 7545 °F) (extrapolatit)
Density (near r.t.)	alpha: 20.45 g/cm3 ; acceptit staundart value: 19.38 g/cm3
Heat o fusion	5.19 kJ/mol
Heat o vapourisation	336 kJ/mol
Molar heat capacity	29.46 J/(mol·K)
Atomic properties
Oxidation states	+2, +3, +4, +5, +6, +7 (an amphoteric oxide)
Electronegativity	Pauling scale: 1.36
Ionisation energies	1st: 604.5 kJ/mol ; ;
Atomic radius	empirical: 155 pm
Covalent radius	190±1 pm
	Colour lines in a spectral rangeSpectral lines o neptunium
Ither properties
Creestal structur	orthorhombic
Thermal conductivity	6.3 W/(m·K)
Electrical resistivity	1.220 µΩ·m (at 22 °C)
Magnetic orderin	paramagnetic
CAS Nummer	7439-99-8
History
Namin	efter planet Neptune, itsel named efter Roman god o the sea Neptune
Diskivery	Edwin McMillan an Philip H. Abelson (1940)
Main isotopes o neptunium
β−	236Pu
α	232Pa
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style="text-align:left"\| data m.p. cat v
	in	calc from C	diff	report	ref
C	639	—	—
K	912	912	0
F	1182	1182	0
WD
input	C: 639±3, K: 912±3, F: 1182±5
comment

style="text-align:left"\| data b.p. cat v
	in	calc from C	diff	report	ref
C	4174	—	—
K	4447	4447	0
F	7545	7545	0
WD
input	C: 4174, K: 4447, F: 7545
comment	(extrapolatit)

References

↑ Sanchez, Rene G.; Loaiza, David J.; Kimpland, Robert H.; Hayes, David K.; Cappiello, Charlene C.; Myers, William L.; Jaegers, Peter J.; Clement, Steven D.; Butterfield, Kenneth B. "Criticality of a ²³⁷Np Sphere" (PDF). Japanese Atomic Energy Agency. Retrieved 6 August 2014.
↑ Np(II), (III) and (IV) have been observed, see Dutkiewicz, Michał S.; Apostolidis, Christos; Walter, Olaf; Arnold, Polly L (2017). "Reduction chemistry of neptunium cyclopentadienide complexes: from structure to understanding". Chem. Sci. 8 (4): 2553–2561. doi:10.1039/C7SC00034K. PMC 5431675. PMID 28553487.
↑ Magnetic susceptibility of the elements and inorganic compounds, in Handbook of Chemistry and Physics 81st edition, CRC press.