REFER : optical rotatory dispersion

Optical rotation is the turning plane of linearly polarized light as it travels through certain materials. Specific rotation is the property of a chemical compound as the change in orientation of a plane of light.

Probably nothing. There is no reference to it to be found anywhere.

Optical isomers are those which have one or more asymmetric carbon atoms their optical activity means a tendency to rotate the plane of plane polarized light but some of such molecules have an internal symmetry as meso form of Tartaric acid , this is the optical isomer of Tartaric acid but is optically inactive.

Ground (0 v) is reference

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