Search results
Results from the WOW.Com Content Network
Protactinium forms mixed binary oxides with various metals. With alkali metals A, the crystals have a chemical formula APaO 3 and perovskite structure; A 3 PaO 4 and distorted rock-salt structure; or A 7 PaO 6, where oxygen atoms form a hexagonal close-packed lattice. In all of these materials, the protactinium ions are octahedrally coordinated.
A Magic Triangle image mnemonic - when the terms of Ohm's law are arranged in this configuration, covering the unknown gives the formula in terms of the remaining parameters. It can be adapted to similar equations e.g. F = ma, v = fλ, E = mcΔT, V = π r 2 h and τ = rF sinθ.
Protactinium-231 is the longest-lived isotope of protactinium, with a half-life of 32,760 years. In nature, it is found in trace amounts as part of the actinium series , which starts with the primordial isotope uranium-235 ; the equilibrium concentration in uranium ore is 46.55 231 Pa per million 235 U.
Theoretical chemistry requires quantities from core physics, such as time, volume, temperature, and pressure.But the highly quantitative nature of physical chemistry, in a more specialized way than core physics, uses molar amounts of substance rather than simply counting numbers; this leads to the specialized definitions in this article.
However, the 231 Pa (with a half-life of 3.27 × 10 4 years) formed via (n,2n) reactions with 232 Th (yielding 231 Th that decays to 231 Pa), while not a transuranic waste, is a major contributor to the long-term radiotoxicity of spent nuclear fuel. While 231 Pa can in principle be converted back to 232
Isotherms of an ideal gas for different temperatures. The curved lines are rectangular hyperbolae of the form y = a/x. They represent the relationship between pressure (on the vertical axis) and volume (on the horizontal axis) for an ideal gas at different temperatures: lines that are farther away from the origin (that is, lines that are nearer to the top right-hand corner of the diagram ...
The distances relevant to the physics expressed in SI units are naturally on the order of , while expressed in atomic units distances are on the order of (one Bohr radius, the atomic unit of length). An additional benefit of expressing quantities using atomic units is that their values calculated and reported in atomic units do ...
Venn was born and raised in Toronto, Canada, where she completed her BSc in Physics & Astronomy at the University of Toronto in 1987. She then received her PhD in Astronomy from the University of Texas at Austin in 1994 working with Christopher Sneden and David L. Lambert on the evolution of massive stars, and pursued postdoctoral research at the Max Planck Institute for Astrophysics ...