- 1The eighteenth letter of the Greek alphabet (Σ, σ), transliterated as ‘s.’.
More example sentences
- The form ς is used instead of σ at the end of a word. The uncial form, called lunate sigma and resembling the letter C, is also sometimes used
- He coined this latter term and employed the Greek letter lower case sigma to denote its population parameter.
- Alpha, rho, tau, sigma, omega, Ash went over the letters he saw in his mind while Lari just stared, apparently in her own little world.
- Finally, even if epsilon is the correct reading, in the letter space to its right, where Meritt read part of an iota, are traces of what appears to be a sigma.
- 2 (Sigma) [followed by Latin genitive] Astronomy The eighteenth star in a constellation: Sigma OctantisMore example sentences
- Finally, the final green beam of light was shot straight up at the constellation Sigma.
- 3 Chemistry & Physics Relating to or denoting an electron or orbital with zero angular momentum around an internuclear axis.More example sentences
- These conical intersections are fundamentally different from the ‘H-vinyl’ structures found in simple alkenes because they involve the interaction of four sigma electrons, as opposed to two pi electrons and two sigma electrons.
- The sigma bond occupies the internuclear space, and the two pi bonds are at 90° angles to each other surrounding the carbon-carbon internuclear space.
- The triple bond is composed of one sigma bond from overlap of sp hybrid orbitals, and two pi bonds, from overlap of two sets of p orbitals.
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More definitions of sigmaDefinition of sigma in:
- The British & World English dictionary