A silvery, metallic, naturally radioactive element, atomic quantity 93, the first of transuranium elements. Its longest-lived isotope is Np-237 with a half-life of 2.1 million many years. Found in trace amounts in uranium ores, it's created synthetically by nuclear reactions. See Table at element.
The transuranic substance element with atomic number 93 and logo Np.
A radioactive metallic part of atomic number 93, manufactured in atomic reactors from Plutonium or Uranium. Expression Np; The atomic fat of the very most steady isotope is 237.0482.
In chem., a supposed brand new element launched by Hermann in 1877 as within columbite and ferro-ilmenite. Its existence will not be confirmed.
a radioactive transuranic metallic element; present trace quantities in uranium ores; a by-product of production of plutonium