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Neptunium

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Identification
Molecular formula
Np
CAS number
7439-99-8
IUPAC name
neptunium
State
State

At room temperature, neptunium is a solid. It belongs to the actinide series and shares properties common among the actinides, such as high density and a capability to form complex compounds, but primarily exists in metallic form under standard conditions.

Melting point (Celsius)
644.00
Melting point (Kelvin)
917.00
Boiling point (Celsius)
3 902.00
Boiling point (Kelvin)
4 175.00
General information
Molecular weight
237.05g/mol
Molar mass
237.0480g/mol
Density
20.4500g/cm3
Appearence

Neptunium is a silvery metal in appearance. When it is freshly prepared, it may have a glossy sheen, but it tarnishes upon exposure to air, forming a surface layer of neptunium oxide that is dull. This metal is also malleable and ductile.

Comment on solubility

Solubility of Neptunium Compounds

Neptunium (Np) is a member of the actinide series and forms various compounds, each with differing solubility characteristics.

Key Considerations for Solubility:

  • Oxidation States: Neptunium can exist in multiple oxidation states (commonly +3, +4, +5, and +6), which affects the solubility of its compounds. For example, NpO2 (neptunium dioxide) is generally insoluble in water, whereas Np(NO3)5 (neptunium(V) nitrate) is more soluble.
  • Environmental Factors: The solubility of neptunium compounds is also influenced by pH levels, temperature, and the presence of other ions in solution.
  • Geochemistry: Neptunium species can form complexes with carbonate, which can enhance their solubility in natural waters, particularly in high pH conditions.

As noted by researchers, "The solubility of neptunium compounds in aqueous environments is essential for understanding its mobility and potential bioavailability." This highlights the importance of studying neptunium's solubility not only for environmental science but also for further advancements in nuclear chemistry and waste management.

Ultimately, the solubility of neptunium is a complex interplay of factors, and ongoing research continues to shed light on the behavior of this intriguing element in various conditions.

Interesting facts

Interesting Facts about Neptunium

Neptunium, represented by the symbol Np, is a fascinating element in the actinide series of the periodic table. Here are some intriguing aspects of neptunium:

  • Discovery: Neptunium was first synthesized in 1940 by Edwin McMillan and Philip H. Abelson at the University of California, Berkeley. They achieved this by bombarding uranium with neutrons. It was a significant achievement in the field of nuclear chemistry.
  • Named After: The name neptunium is derived from Neptune, the eighth planet in our solar system, following the theme set by its predecessor uranium, which is named after Uranus.
  • Radioactive Nature: Neptunium is radioactive and has a variety of isotopes, with 237Np being the most prevalent and long-lived. This isotope has a half-life of about 2.14 million years!
  • Applications: Neptunium has several emerging applications, including its use in the production of certain isotopes for nuclear reactors and in the development of advanced nuclear fuel cycles. Additionally, research is being conducted to explore its potential in radiation detection and as a source for neutron radiography.
  • Environment and Safety: As a radioactive element, neptunium must be handled with caution. It poses potential hazards due to its radiotoxicity, making understanding its behavior in the environment critical for safety.
  • Interesting Chemistry: Neptunium can exhibit multiple oxidation states ranging from -3 to +7, highlighting its versatility and complexity in chemical reactions. This allows chemists to explore a variety of chemical processes involving Np.

Neptunium remains a subject of intense study due to its potential uses and the challenges associated with its management and safety. As the first transuranic element, it opens up discussions in nuclear chemistry and the future of nuclear engineering.

Synonyms
NEPTUNIUM
7439-99-8
neptunio
neptunium atom
UNII-6200K977BQ
NEPTUNIUM [MI]
NEPTUNIUM [HSDB]
EINECS 231-108-8
6200K977BQ
NEPTUNIUM, ELEMENTAL
DTXSID5074840
CHEBI:33387
DTXCID3047639
231-108-8
Np
Np6
Neptunium(5+)
Neptunium ion(5 )
Neptunium ion(6 )
Neptunium, ion(Np5 )
Neptunium, ion(Np6 )
Neptunium, ion (Np4+)
93Np
LFNLGNPSGWYGGD-UHFFFAOYSA-N
NS00081811
Q1105