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uraniumneptuniumplutonium
Pm
Np
  
 
 
General
Name, Symbol, NumberNeptunium, Np, 93
Chemical series Actinides
Period, Block 7 , f
Density, Hardness 20250 kg/m3Kilogram per cubic metre is the SI measure of density and is represented as kg/m³, where kg stands for kilogram and m³ stands for cubic metre. The density of water is about 1000 kg/m³, since a cubic metre of water weighs about a tonne. kg/m³" is sometimes, n/a
AppearanceFor alternative meanings, see color (disambiguation). visual arts. Color (or colour is a sensation which (in humans) derives from the ability of the fine structure of the eye to distinguish three differently filtered analyses of a view. The perception of Silvery metallic
Atomic properties
Atomic weightIn reference to a certain isotope of a chemical element, atomic weight (more accurately relative atomic mass though also called simply atomic mass is the mass of one atom of the isotope expressed in units atomic mass unit amu) such that the Carbon-12 isot 1 E-25 kg|[237] u]]
Atomic radiusAtomic radius is the distance from the atomic nucleus to the outmost stable electron orbital in a atom that is at equilibrium and is measured in picometers or Angstroms. Atomic radii are called covalent radii (a reference to the types of bonds formed) whe (calc.) 175 (ND) pmTo help compare different orders of magnitude this page lists lengths between 100 pm and 1 nm (10-10 m and 10-9 m). See also lengths of other orders of magnitude. Lengths shorter than 100 pm 100 pm 1 Angstrom 100 pm (0. 1 nm) covalent radius of sulfur ato
Covalent radiusCovalent radius in chemistry corresponds to half of the distance between two identical atomic nuclei, bound by a covalent bond. It is expressed in terms of pm or A. Chemistry. ND pmPicometre ( American spelling: picometer is an SI measure of length that is equal to 10−12 of a metre. Its symbol is pm and it is commonly used in measuring atomic-scale distances. Atom diameters are in the range from ~30 to 600 pm. 1 pm 1 × 10&minu
van der Waals radiusThe van der Waals radius of an atom is the radius of an imaginary hard sphere which can be used to model the atom for many purposes. Van der Waals radii are determined from measurements of atomic spacing between pairs of unbonded atoms in crystals. The va ND pm
Electron configuration [ Rn] 5f46 d17 s2
e- 's per energy level2,8,18,32,22,9,2
Oxidation states ( Oxide) 6, 5, 4, 3 ( amphoteric)
Crystal structure 3 forms: orthorhombic,
tetragonal and cubic
Physical properties
State of matter Solid ( _)
Melting point 910 K (1179° F)
Boiling point 4273 K (7232 °F)
Molar volume 11.59 ×10-6 m3/mol
Heat of vaporization ND kJ/mol
Heat of fusion 5.19 kJ/mol
Vapor pressure ND Pa at 1323 K
Velocity of sound ND m/s at 293.15 K
Miscellaneous
Electronegativity 1.36 ( Pauling scale)
Specific heat capacity unknown J/(kg*K)
Electrical conductivity 0.822 106/m ohm
Thermal conductivity 6.3 W/(m*K)
1st ionization potential 604.5 kJ/mol
Most stable isotopes
iso NA half-life DM DE M eV DP
235Np {syn.} 396.1 d α
ε
5.192
0.124
231 Pa
235 U
236Np{syn.} 154 E3 y ε
β-
α
0.940
0.940
5.020
236U
236 Pu
232Pa
237Np{syn.} 2.144 E6 y SF & α4.959233Pa
SI units & STP are used except where noted.

Neptunium is a synthetic element in the periodic table that has the symbol Np and atomic number 93. A silvery radioactive metallic element, neptunium is the first transuranic element and belongs to the actinide series. Its most stable isotope, neptunium-237 is a by-product of nuclear reactors and plutonium production and it can be used as a component in neutron detection equipment. Neptunium is also found in trace amounts in uranium ores.





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