The tendency of an atom to attract electrons towards itself, expressed on a relative scale. \[\ce{_{91}^{234}Pa} \rightarrow \ce{_{-1}^0e} + \ce{_{92}^{234}U} \label{nuke1}\] Once again, the atomic number increases by one and the mass number remains the same; confirm that the equation is correctly balanced. Name: Uranium Symbol: U Atomic Number: 92 Atomic Mass: 238.0289 amu Melting Point: 1132.0 °C (1405.15 K, 2069.6 °F) Boiling Point: 3818.0 °C (4091.15 K, 6904.4 °F) Number of Protons/Electrons: 92 Number of Neutrons: 146 Classification: Rare Earth Crystal Structure: Orthorhombic Density @ 293 K: 18.95 g/cm 3 Color: silverish Atomic Structure Uranium-234 has the shortest half-life of them all at 245,500 years, but it occurs only indirectly from the decay of U-238. Uranium's most stable isotope, uranium-238, has a half-life of about 4,468,000,000 years. When refined, uranium is a silvery-white metal. Number of protons 92 (as for all U isotopes), neutrons 142, electrons 92. 234 U: 234.040946: 0.005%: 0 : 235 U: 235.043924: 0.720%: 7/2-0.35: 238 U: 238.050784: 99.275%: 0 : U I Ground State 1s 2 2s 2 2p 6 3s 2 3p 6 3d 1 0 4s 2 4p 6 4d 1 0 … Naturally-occurring uranium contains approximately 99.28305 by weight U-238, 0.7110% U-235, and 0.0054% U-234. First ionisation energy The minimum energy required to remove an electron from a neutral atom in its ground state. Only U-235 (contained in natural uranium at 0.711 weight %, or 0.72 atom%) is fissionable, and therefore able to release energy in a nuclear fission reactor. All of the isotopes are radioactive. U-238 and U-235 are the parent nuclides of two independent decay series, while U-234 is a decay product of the U-238 series. Uranium (chemical symbol U) is a naturally occurring radioactive element. The difference in atomic mass (that's the 234 here) is due to difference in number of neutrons. It decays into thorium-234 through alpha decay or decays through spontaneous fission. When 235 92 U nuclides are bombarded with neutrons, one of the many fission reactions that it can undergo is the following (shown in the adjacent image): Other uranium compounds have also been used to make vaseline glass and glazes. Uranium has three primary naturally occurring isotopes isotopeA form of an element that has the same number of protons but a different number of neutrons in the nucleus, giving it a different atomic mass. The percentage weight of U-235 in natural uranium depends on its source and may vary by as much as 0.1%. 1/2 life is 245,500 years. Uranium has sixteen isotopes. … Atomic mass is calculated (#of protons + # of neutrons), so Uranium-234 has 92 protons and 142 neutrons. U234 occurs naturally in small amounts, 0.0054 percent of total U. The fission of one atom of uranium-235 releases 202.5 MeV (3.24 × 10 −11 J) inside the reactor.That corresponds to 19.54 TJ/mol, or 83.14 TJ/kg. The decay chain of uranium-238 to uranium-234 and eventually lead-206 involves emission of eight alpha particles in a time (hundreds of thousands of years) short compared to the half-life of 238 U, so that a sample of 238 U in equilibrium with its decay products (as in natural uranium ore) will have eight times the alpha activity of 238 U alone. In comparison, the most radioactive element is polonium . The uranium within these items is radioactive and should be treated with care. Another 8.8 MeV escapes the reactor as anti-neutrinos. Protactinium-234 is also a beta emitter and produces uranium-234.