Search results
Results From The WOW.Com Content Network
Neptunium is a chemical element; it has symbol Np and atomic number 93. A radioactive actinide metal, neptunium is the first transuranic element. It is named after Neptune, the planet beyond Uranus in the Solar System, which uranium is named after. A neptunium atom has 93 protons and 93 electrons, of which seven are valence electrons.
Np. Trace quantities are found in nature from neutron capture reactions by uranium atoms, a fact not discovered until 1951. [2] Twenty-five neptunium radioisotopes have been characterized, with the most stable being 237 Np with a half-life of 2.14 million years, 236 Np with a half-life of 154,000 years, and 235 Np with a half-life of 396.1 days.
A wide variety of neptunium sulfide compounds have been characterized, including the pure sulfide compounds NpS, NpS 3, Np 2 S 5, Np 3 S 5, Np 2 S 3, and Np 3 S 4. Of these, Np 2 S 3 , prepared by reacting NpO 2 with hydrogen sulfide and carbon disulfide at around 1000 °C, is the most well-studied and three allotropic forms are known.
Spectral lines of neptunium: Other properties; Natural occurrence: from decay: Crystal structure
Neptunium monocarbide is a binary compound of neptunium metal and carbon with the chemical formula NpC. [1] [2] Preparation ... Physical properties
Neptunium(IV) phosphide can be formed from the fusion of stoichiometric amounts of neptunium and red phosphorus in an evacuated and sealed quartz tube at 750 °C: [2] [3] 3Np + 4P → Np 3 P 4 Physical properties
the reaction of neptunium nitride with HCl: [3] 2 NpN + 8 HCl → N 2 + 4 H 2 + 2 NpCl 4. the reaction of neptunium sulfide with HCl: Np 2 S 3 + 8 HCl → 2 NpCl 4 + 3 H 2 S + H 2. the reaction of carbon tetrachloride with neptunium(IV) oxide or NpO 2. Neptunium tetrachloride is formed as a yellow sublimate. [4] NpO 2 + CCl 4 → NpCl 4 + CO 2 ...
Neptunium(III) phosphide is a binary inorganic compound of neptunium metal and phosphorus with the chemical formula NpP. [2] Preparation ... Physical properties