WebElements Periodic Table of the Elements | Neptunium

Neptunium: the essentials

Neptunium is a radioactive rare earth metal and has at least 3 allotropic forms. It is named for the planet Neptune. Np-237 is a by-product from nuclear reactors.

Table: basic information about and classifications of neptunium.
Name: Neptunium Symbol: Np Atomic number: 93 Atomic weight: [ 237 ] Standard state: solid at 298 K CAS Registry ID: 7439-99-8	Group in periodic table: Group name: Actinoid Period in periodic table: 7 (actinoid) Block in periodic table: f-block Colour: silvery metallic Classification: Metallic

Neptunium: historical information

Neptunium was discovered by Edwin M. McMillan and P. H. Abelson at 1940 in USA. Origin of name: named after "the planet Neptune".

Neptunium was the first synthetic transuranium element of the actinide series. It was discovered by McMillan and Abelson in 1940 at Berkeley, California, USA, who bombarded uranium with neutrons produced from a cyclotron. It was the first synthetic transuranium (elements after uranium) element discovered.

Neptunium: physical properties

Melting point: 910 [or 637 °C (1179 °F)] K
Boiling point: 4300 [or ca. 4000 °C (7232 °F)] K
Density of solid: 20450 kg m^-3

Ground state electron configuration: [Rn].5f⁴.6d¹.7s²
Shell structure: 2.8.18.32.22.9.2
Term symbol: ⁶L_11/2
Pauling electronegativity: 1.36 (Pauling units)
First ionisation energy: 604.5 kJ mol^-1
Second ionisation energy: no data kJ mol^-1

Isolation

Isolation: coming soon!

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Nd	Pm	Sm
U	Np	Pu

Neptunium	Neptunium
Neptunium	Neptunium
Nettunio	Neptunio
Neptunium	Neptúnio

Neptunium
- Essential data: names, symbol, atomic number, and atomic weight; block, period, and group in periodic table; description; standard state; registry number; and isolation
- History: meaning of name; discovery; and history of the element
- Uses
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Neptunium around us
- Geology: Abundance of elements in the universe; the sun; meteorites; Earth's crust; oceans; and streams
- Biology: Abundance in humans; biological role; and health hazards)
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Chemistry and compounds
- Compounds: halides, oxides, sulfides, hydrides, and complexes; lattice energies; and reduction potentials
- Reactions of neptunium: reactions of neptunium with air; water; halogens; acids; and bases
- Electronegativities: Pauling; Sanderson; Allred Rochow; Mulliken-Jaffe; and Allen
- Bond enthalpies of diatomic species
- Lattice energies
Element properties
- Physics properties: Boiling point; melting point; density; molar volume; thermal conductivity; and electrical resistivity; bulk modulus; critical temperature; superconductivity temperature; hardness (mineralogical, Brinell, and Vickers); linear expansion coefficient; Poisson's ratio; reflectivity; refractive index; rigidity modulus; Young's modulus; velocity of sound
- Crystal structure
- Thermochemistry: enthalpies of atomization, fusion, and vaporization; thermodynamic properties
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Atom properties
- Electron shell properties: Electronic configuration; term symbol; electron affinity; ionization energies; and atomic spectra
- Atom sizes: atomic radius; Shannon and Pauling ionic radii; covalent radius; metallic radius; element bond length; and Van der Waals radius
- Atomic orbital properties: effective nuclear charge; electron binding energies; and valence orbital radii maxima
Nuclear properties
- Isotopes: isotope abundances; radioactive isotopes; isotope masses; nuclear spins; and nuclear magnetic moment
- NMR properties: frequencies; isotopes; magnetogyric ratios; quadrupole moments; receptivities; and relative sensitivities
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1	2															3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18

1 H																															2 He
3 Li	4 Be																									5 B	6 C	7 N	8 O	9 F	10 Ne
11 Na	12 Mg																									13 Al	14 Si	15 P	16 S	17 Cl	18 Ar
19 K	20 Ca															21 Sc	22 Ti	23 V	24 Cr	25 Mn	26 Fe	27 Co	28 Ni	29 Cu	30 Zn	31 Ga	32 Ge	33 As	34 Se	35 Br	36 Kr
37 Rb	38 Sr															39 Y	40 Zr	41 Nb	42 Mo	43 Tc	44 Ru	45 Rh	46 Pd	47 Ag	48 Cd	49 In	50 Sn	51 Sb	52 Te	53 I	54 Xe
55 Cs	56 Ba	57 La	58 Ce	59 Pr	60 Nd	61 Pm	62 Sm	63 Eu	64 Gd	65 Tb	66 Dy	67 Ho	68 Er	69 Tm	70 Yb	71 Lu	72 Hf	73 Ta	74 W	75 Re	76 Os	77 Ir	78 Pt	79 Au	80 Hg	81 Tl	82 Pb	83 Bi	84 Po	85 At	86 Rn
87 Fr	88 Ra	89 Ac	90 Th	91 Pa	92 U	93 Np	94 Pu	95 Am	96 Cm	97 Bk	98 Cf	99 Es	100 Fm	101 Md	102 No	103 Lr	104 Rf	105 Db	106 Sg	107 Bh	108 Hs	109 Mt	110 Ds	111 Rg	112 Cn	113 Uut	114 Fl	115 Uup	116 Lv	117 Uus	118 Uuo

Neptunium

Neptunium: the essentials

Neptunium: historical information

Neptunium: physical properties

Neptunium: orbital properties

Isolation

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