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The lasers needed for the magneto-optical trapping of rubidium 85: (a) & (b) show the absorption (red detuned to the dotted line) and spontaneous emission cycle, (c) & (d) are forbidden transitions, (e) shows that if the cooling laser excites an atom to the = state, it is allowed to decay to the "dark" lower hyperfine, F=2 state, which would ...
The MOT explains the paramagnetic nature of O 2, which valence bond theory cannot explain. In molecular orbital theory, electrons in a molecule are not assigned to individual chemical bonds between atoms , but are treated as moving under the influence of the atomic nuclei in the whole molecule. [ 1 ]
The F 2 molecule is commonly described as having exactly one bond (in other words, a bond order of 1) provided by one p electron per atom, as are other halogen X 2 molecules. However, the heavier halogens' p electron orbitals partly mix with those of d orbitals, which results in an increased effective bond order; for example, chlorine has a ...
In agreement with this description the photoelectron spectrum for water shows a sharp peak for the nonbonding 1b 1 MO (12.6 eV) and three broad peaks for the 3a 1 MO (14.7 eV), 1b 2 MO (18.5 eV) and the 2a 1 MO (32.2 eV). [29] The 1b 1 MO is a lone pair, while the 3a 1, 1b 2 and 2a 1 MO's can be localized to give two O−H bonds and an in-plane ...
2 KMnO 4 + 2 KF + 10 HF + 3 H 2 O 2 → 2 K 2 MnF 6 + 8 H 2 O + 3 O 2 ↑ 2 K 2 MnF 6 + 4 SbF 5 → 4 KSbF 6 + 2 MnF 3 + F 2 ↑. Christe later commented that the reactants "had been known for more than 100 years and even Moissan could have come up with this scheme." [178] As late as 2008, some references still asserted that fluorine was too ...
Henri Moissan's 1892 record of fluorine gas color, viewed end-on in a 5‑m tube. Air (1) is on the left, fluorine (2) is in the middle, chlorine (3) is on the right. Fluorine forms diatomic molecules (F 2) that are gaseous at room temperature with a density about 1.3 times that of air.
The only chemical elements that form stable homonuclear diatomic molecules at standard temperature and pressure (STP) (or at typical laboratory conditions of 1 bar and 25 °C) are the gases hydrogen (H 2), nitrogen (N 2), oxygen (O 2), fluorine (F 2), and chlorine (Cl 2), and the liquid bromine (Br 2). [1]
The F-gas Regulation adopts an approach based on containment and recovery of F-gases as well as imposing obligations on reporting, training and labeling on those using F-gases. On 26 September 2011, the Commission issued a report on the application, effects and adequacy of the Regulation, drawing from the results of an analytical study it ...