Neptunium (Np)

Properties

Abundance
CAS Number	7439-99-8
PubChem CID	na
Atomic Radius	155
Atomic Volume	11.62
Atomic Weight	[237]
Block	f
Boiling Point	4,000
Bulk Modulus
Category	Actinides
Crystal Structure	Simple Orthorhombic
Color	Silver
Covalent Radius	190
Density	20.45
Electrical Resistivity
Electron Configuration	[Rn] 5f⁴ 6d¹ 7s²
Electrons per shell	2, 8, 18, 32, 22, 9, 2
Electronegativity	1.36
Electrons	93
Group	na
Heat of Fusion	10
Heat of Vaporization	335
Ionization Potential	6.266
Magnetic Ordering
Magnetic Susceptibility
Mass	[237]
Mass Number	93
Melting Point	637
Name	Neptunium
Neutrons	144
Atomic Number	237
Oxidation States	3, 4, 5, 6, 7
Period	7
Phase	Solid
Poisson Ratio
Protons	93
Shear Modulus
Specific Heat Capacity	-
Symbol	Np
Thermal Conductivity	0.063
Van der Waals radius
Young's Modulus
Abundance in Earth's crust	na
Abundance in Universe	na

Np Neptunium 93 (237) 7 f 93 640.0 3900.0 [Rn] 5f4 6d1 7s2 2 8 18 32 22 9 2 20.2 None Silver Orthorhombic 1.4 {"1":"604.5"} 605 +5,3,4,6 1.3 21.1 6.3 1 2.1455×10⁶⁶y AlphaEmission Solid, Conductor, Actinide, Radioactive, Synthetic nep-TOO-ni-em Rare, silvery radioactive metal. It has no significant commercial applications. Produced by bombarding uranium with slow neutrons. AFo96BkYNdQ Neptunium

Iridium was discovered in 1803 by English chemist Smithson Tennant in London.

Chemists who studied platinum dissolved it in aqua regia to create soluble salts and observed a small amount of a dark, insoluble residue.

Smithson Tennant analyzed the insoluble residue and concluded that it must contain a new metal. From the Latin word iris meaning rainbow 93 1940 Edwin M. McMillan and P. H. Abelson USA Named after "the planet Neptune"

Isotopes of Iridium

Standard Atomic Weight

[237]

Stable Isotopes

Unstable Isotopes

²²⁵Np ²²⁶Np ²²⁷Np ²²⁸Np ²²⁹Np ²³⁰Np ²³¹Np ²³²Np ²³³Np ²³⁴Np ²³⁵Np ²³⁶Np ²³⁷Np ²³⁸Np ²³⁹Np ²⁴⁰Np ²⁴¹Np ²⁴²Np ²⁴³Np ²⁴⁴Np

Iridium is considered to be of low toxicity

Iridium is the most corrosion-resistant metal known

Iridium is used in making crucibles and other equipment that is used at high temperatures.

Iridium is also used as a hardening agent in platinum alloys.

Its resistance to arc erosion makes iridium alloys ideal for electrical contacts for spark plugs.

Radioactive isotopes of iridium are used in radiation therapy for the treatment of cancer.

Neptunium on ChemicalAid