Chirality

From Wikipedia, the free encyclopedia

For the manga by Satoshi Urushihara, see Chirality (manga).

Chirality (Greek handedness, derived from the word stem χειρ~, ch[e]ir~ - hand~) is an asymmetry property important in several branches of science. An object or a system is called chiral if it differs from its mirror image, and its mirror image cannot superimpose on the original object. A chiral object and its mirror image are called enantiomorphs (Greek opposite forms) or, when referring to molecules, enantiomers. A non-chiral object is called achiral (sometimes also amphichiral) and can be superimposed on its mirror image.

Chirality may also refer to:

• Chirality (chemistry) of some molecules
• Chirality (mathematics) of mathematical objects
• Chirality (physics) of some subatomic particles
• The chirality of certain crystalline solids. Of the 230 existing space groups 65 are chiral. Sodium chlorate is an achiral ionic compound but crystallizes in a chiral P2₁3 space group. An example of an achiral organic compound forming chiral crystals is benzil. Racemic acid is the racemic form of tartaric acid forming a mixture of two enantiomorphic crystals each form consisting of one of the two enantiomers.
• The chirality of surfaces. Materials with bulk chirality can be cleaved exposing a chiral surface.
• The chirality of supermarkets. This informal usage, increasingly common on Usenet, refers to the relative placing of the entrance and the tills.