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Naturally occurring chromium (24 Cr) is composed of four stable isotopes; 50 Cr, 52 Cr, 53 Cr, and 54 Cr with 52 Cr being the most abundant (83.789% natural abundance). 50 Cr is suspected of decaying by β + β + to 50 Ti with a half-life of (more than) 1.8×10 17 years.
Chromium compounds are compounds containing the element chromium (Cr). Chromium is a member of group 6 of the transition metals . The +3 and +6 states occur most commonly within chromium compounds, followed by +2; charges of +1, +4 and +5 for chromium are rare, but do nevertheless occasionally exist.
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Naturally occurring chromium is composed of four stable isotopes; 50 Cr, 52 Cr, 53 Cr and 54 Cr, with 52 Cr being the most abundant (83.789% natural abundance). 50 Cr is observationally stable , as it is theoretically capable of decaying to 50 Ti via double electron capture with a half-life of no less than 1.3 × 10 18 years.
A cognitive radio (CR) is a radio that can be programmed and configured dynamically to use the best channels in its vicinity to avoid user interference and congestion. Such a radio automatically detects available channels, then accordingly changes its transmission or reception parameters to allow more concurrent wireless communications in a given band at one location.
Fundamentally, the Hume-Rothery rules are restricted to binary systems that form either substitutional or interstitial solid solutions. However, this approach limits assessing advanced alloys which are commonly multicomponent systems. Free energy diagrams (or phase diagrams) offer in-depth knowledge of equilibrium restraints in complex systems.
The Cr centres are octahedral, being distorted by the Jahn-Teller Effect. [8] Ball-and-stick model of chromium(II) chloride tetrahydrate. The hydrated derivative, CrCl 2 (H 2 O) 4, forms monoclinic crystals with the P2 1 /c space group. The molecular geometry is approximately octahedral consisting of four short Cr—O bonds (2.078 Å) arranged ...
Coupled substitution is the geological process by which two elements simultaneous substitute into a crystal in order to maintain overall electrical neutrality and keep the charge constant. [1] In forming a solid solution series, ionic size is more important than ionic charge , as this can be compensated for elsewhere in the structure.