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Hydrogen peroxide (H 2 O 2) is a nonplanar molecule with (twisted) C 2 symmetry; this was first shown by Paul-Antoine Giguère in 1950 using infrared spectroscopy.Although the O−O bond is a single bond, the molecule has a relatively high rotational barrier of 386 cm −1 (4.62 kJ/mol) for rotation between enantiomers via the trans configuration, and 2460 cm −1 (29.4 kJ/mol) via the cis ...
Bayes' theorem is named after the Reverend Thomas Bayes ( / beɪz / ), also a statistician and philosopher. Bayes used conditional probability to provide an algorithm (his Proposition 9) that uses evidence to calculate limits on an unknown parameter. His work was published in 1763 as An Essay towards solving a Problem in the Doctrine of Chances.
Value in joules per kelvin: 1.380 649 × 10−23 J⋅K−1 [1] The Boltzmann constant ( kB or k) is the proportionality factor that relates the average relative thermal energy of particles in a gas with the thermodynamic temperature of the gas. [2] It occurs in the definitions of the kelvin (K) and the gas constant, and in Planck's law of black ...
the free encyclopedia that anyone can edit. "The Day Before the Revolution" is a science fiction short story by American writer Ursula K. Le Guin (pictured). First published in Galaxy in August 1974, it was republished in Le Guin's The Wind's Twelve Quarters (1975). Set in her fictional Hainish universe, the story has strong connections to her ...
The golden ratio was called the extreme and mean ratio by Euclid, and the divine proportion by Luca Pacioli, and also goes by several other names. Mathematicians have studied the golden ratio's properties since antiquity. It is the ratio of a regular pentagon's diagonal to its side and thus appears in the construction of the dodecahedron and icosahedron.
The word psychopathy is a joining of the Greek words psyche ( ψυχή) "soul" and pathos ( πάθος) "suffering, feeling". [17] The first documented use is from 1847 in Germany as psychopatisch, [18] and the noun psychopath has been traced to 1885. [19] In medicine, patho- has a more specific meaning of disease (Thus pathology has meant the ...
Graphene is an atomic-scale hexagonal lattice made of carbon atoms. Graphene (/ ˈ ɡ r æ f iː n /) is an allotrope of carbon consisting of a single layer of atoms arranged in a hexagonal lattice nanostructure. The name is derived from "graphite" and the suffix -ene, reflecting the fact that the graphite allotrope of carbon contains numerous double bonds.
