Neptunium, Chemical Properties, Applications and Effects, Uses, Questions (For CBSE, ICSE, IAS, NET, NRA 2022)

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Neptunium Symbols
Atomic Number
Atomic Mass
Discovered byEdwin McMillan and Philip Abelson in 1940

Chemical Properties of Neptunium

Chemical Properties of Neptunium
GroupActinidesMelting Point

Period7Boiling Point

Atomic number93Relative atomic mass
State at SolidKey isotopes
Electron configuration

CAS number
  • Neptunium has an atomic number of 93, present in the actinide series of on the Periodic Table.
  • Neptunium is found between uranium (92) , the last of the natural elements, and plutonium (94) .
  • Like its two closest Neighbours, it belongs to the actinide series, so named because of the chemical affinity with actinium (89) .
  • First, of the artificially produced elements, Np starts the series of the 11 transuranic elements, all radioactive, heavy metals.

Physical Properties of Neptunium

  • Like plutonium and uranium, neptunium (237) is an alpha emitter, which means that as it disintegrates, it emits a particle formed of two protons and two neutrons (similar to a helium nucleus) . It then transmutes into protactinium 233 (element 91) .
  • Neptunium is produced through neutron bombardment of a uranium nucleus.
  • Plutonium 238 is obtained as a result of using Np 237 as a target in research reactors, which constitutes a significant source of energy for space missions.
  • Found in nuclear waste as a mixture with other fission products, Neptunium 237 also appears in increasing quantity as a product of americium 241.

Applications and Effects of Neptunium

  • With a critical mass of 73 kg, Neptunium is considered usable in nuclear weapons. Although, no country is known to have used it to make a nuclear explosive device.
  • Neptunium with no major commercial uses of Np is needed for research and exploratory work.

Uses of Neptunium

  • Neptunium, being a synthetic radioactive element, has no commercial uses at present
  • but it is used to synthesize other elements such as plutonium - 238 etc. It is used as a
  • precursor in plutonium - 238 production. Neptune - 237 is irradiated with neutrons to
  • produce . Reaction is given below –
    • Plutonium - 238 is used in thermal generators, spacecrafts, military applications and as an - emitter. It is used in nuclear fuel as well.
    • Neptunium - 237 is used for detection of high energy neutrons. It can be used in nuclear reactors and nuclear weapons.


What is the Charge of Neptunium?


  • A neptunium atom has 93 protons and 93 electrons, of which seven are valence electrons. Neptunium metal is silvery and tarnishes when exposed to air.
  • The element occurs in three allotropic forms and it normally exhibits five oxidation states, ranging from + 3 to + 7.

Is Neptunium Used in Bombs?


Neptunium is used for bombs, and shouldn՚t be used by Dads or Moms. It isn՚t cheap or plentiful, but it is radioactive and ductile. Its chemical symbol is Np and its atomic number is 93. Its mass is 237 grams.

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