Neptunium (Np) – Periodic Table [Element Information & More]

Neptunium element (Np) is in period 7 of a periodic table. Neptunium is in the f-block and it is classified as an actinide on the periodic table.

There is a lot more information related to neptunium which is mentioned in the Information Table given below.

So let’s dive right into it!

Table of contents

• Neptunium element (Information Table)
• Neptunium element in Periodic table
• Facts about Neptunium
• Properties of Neptunium
• Uses of Neptunium

Neptunium Element (Information Table)

The important data related to neptunium element is given in the table below.

Appearance of neptunium	Silvery metallic
Atomic number of neptunium	93
Symbol of neptunium	Np
Atomic mass of neptunium (most stable isotope)	237 u
Protons, Neutrons & Electrons in neptunium	Protons: 93, Neutrons: 144, Electrons: 93
State of neptunium (at STP)	Solid
Period number of neptunium in periodic table	7
Block of neptunium in periodic table	f-block
Category of neptunium	Inner transition metals
Bohr model or Electrons per shell or Electrons arrangement in neptunium	2, 8, 18, 32, 22, 9, 2
Electron configuration of neptunium	[Rn] 5f4 6d1 7s2
Orbital diagram of neptunium
Atomic radius of neptunium (van der Waals radius)	237 picometers
Density of neptunium	20.45 g/cm3
1st ionization energy of neptunium	6.266 eV
Main isotope of neptunium	237Np
Crystal structure of neptunium	Orthorhombic
Discovery of neptunium	By Edwin McMillan and Philip Abelson (in 1940)

Also see: Interactive Periodic Table (It has rotating bohr models as well as many other details of all the 118 elements in a single periodic table).

Neptunium element in Periodic table

The Neptunium element (Np) has the atomic number 93 and is located in period 7. Neptunium is a metal and it is classified as an actinide group element.

Click on above elements in the periodic table to see their information.

Facts about neptunium

Here are a few interesting facts about the neptunium element.

1. Edwin McMillan and Philip Abelson discovered neptunium in the year 1940.
2. Neptunium was given its name from the planet “Neptune”.
3. The radioactive isotope of neptunium (²³⁷Np) has the longest half-life of around 2.14 million years.
4. Out of all the elements on the periodic table, neptunium is the 5^th most dense element.
5. Neptunium is a radioactive element and it is also toxic for humans.

Properties of neptunium

Here is a list of some physical properties and chemical properties of neptunium.

Physical properties of neptunium

• Neptunium has a silvery white metallic appearance.
• The density of neptunium is 20.45 g/cm³ and the atomic mass of its most stable isotope is 237 amu.
• The atomic radius (van der Waals) of neptunium is 221 picometers.
• Neptunium has orthorhombic crystal structure.

Chemical properties of neptunium

• Neptunium reacts with the atmospheric oxygen and forms a thin oxide layer on it.
• The electron configuration of neptunium ([Rn] 5f⁴ 6d¹ 7s²) shows that the last electron enters the f-orbital and hence it is f-block element.
• Neptunium has variable oxidation states ranging from +3 to +7, but its most common oxidation state is +5.

Uses of neptunium

Here are some uses of the neptunium element.

• Neptunium is a radioactive element and hence it has no commercial uses.
• Neptunium is generally used in research work.
• Neptunium can be used to produce plutonium.

External resources:

1. Neptunium – Element information, properties and uses | Periodic Table. (n.d.). Neptunium – Element Information, Properties and Uses | Periodic Table. https://www.rsc.org/periodic-table/element/93/neptunium
2. Neptunium – Wikipedia. (2014, August 6). Neptunium – Wikipedia. https://en.wikipedia.org/wiki/Neptunium
3. It’s Elemental – The Element Neptunium. (n.d.). It’s Elemental – the Element Neptunium. https://education.jlab.org/itselemental/ele093.html
4. Bondi, A. (1964, March). van der Waals Volumes and Radii. The Journal of Physical Chemistry, 68(3), 441–451. https://doi.org/10.1021/j100785a001
5. Holden, et al. (2018, December 1). IUPAC Periodic Table of the Elements and Isotopes (IPTEI) for the Education Community (IUPAC Technical Report). Pure and Applied Chemistry, 90(12), 1833–2092. https://doi.org/10.1515/pac-2015-0703
6. Zhang, et al. (2011, January 11). Corrected Values for Boiling Points and Enthalpies of Vaporization of Elements in Handbooks. Journal of Chemical & Engineering Data, 56(2), 328–337. https://doi.org/10.1021/je1011086
7. P. (n.d.). Neptunium | Np (Element) – PubChem. Neptunium | Np (Element) – PubChem. https://pubchem.ncbi.nlm.nih.gov/element/Neptunium
8. Atomic Data for Neptunium (Np). (n.d.). Atomic Data for Neptunium (Np). https://physics.nist.gov/PhysRefData/Handbook/Tables/neptuniumtable1.htm
9. C&EN: IT’S ELEMENTAL: THE PERIODIC TABLE – NEPTUNIUM. (n.d.). C&EN: IT’S ELEMENTAL: THE PERIODIC TABLE – NEPTUNIUM. https://pubsapp.acs.org/cen/80th/neptunium.html?
10. D. (2005, November 29). Getting the Neptunium out of Nuclear Waste – Berkeley Lab. Berkeley Lab News Center. https://newscenter.lbl.gov/2005/11/29/getting-the-neptunium-out-of-nuclear-waste/
11. Prohaska, T., et al. (2022, May 1). Standard atomic weights of the elements 2021 (IUPAC Technical Report). Pure and Applied Chemistry, 94(5), 573–600. https://doi.org/10.1515/pac-2019-0603
12. Haynes, W. M. (Ed.). (2014, June 4). CRC Handbook of Chemistry and Physics. https://doi.org/10.1201/b17118
13. Kaye, G W.C., & Laby, T H. Tables of physical and chemical constants. 15th Edition. United States.
14. Sansonetti, J. E., & Martin, W. C. (2005, December). Handbook of Basic Atomic Spectroscopic Data. Journal of Physical and Chemical Reference Data, 34(4), 1559–2259. https://doi.org/10.1063/1.1800011