Isomers  are compounds with the same
   molecular formula but different structures and properties.
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<lI> Structural  isomers  differ  in  the arrangement of their covalent
bonds.
<lI> Geometric  isomers  differ  in their spatial arrangements around a
double bond.
<lI> Enantiomers  (stereo  isomers) are mirror images of each other and
contain an asymmetric carbon.
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