Neptunium

Neptunium is a chemical element that has the symbol Np on the periodic table. It has the atomic number 93 which means it has 93 protons and electrons in its atoms. It is named after the planet Neptune in the same way as Uranium is named after the planet Uranus.

Neptunium was discovered in the year of 1940 by two men named Edwin McMillan and Phillip H. Abelson at Berkeley Radiation Center of the University of California.^[1] It was created by fusing Hydrogen nuclei called protons into the element Uranium.

Neptunium is a radioactive silvery-metallic element that is part of a group of elements called the Actinides, which it shares many similarities to. Its melting point is 637 degrees Celsius, its boiling point is 4000 degrees Celsius, and its atomic mass is 237.

It oxidizes very quickly with multiple different oxidation states. It also bonds with halides and even alkali metals.

Since all isotopes of neptunium have half-lives that are many times shorter than the age of the Earth, any neptunium that was made when the earth was formed should have decayed by now. After only about 80 million years, the concentration of even the longest-lived isotope, ²³⁷Np, would have been reduced to less than one-trillionth (10⁻¹²) of its original amount.

1. ↑ McMillan, Edwin; Abelson, Philip Hauge (1940-06-15). "Radioactive Element 93". Physical Review. 57 (12): 1185–1186. doi:10.1103/PhysRev.57.1185.2.