how do we know if a molecule is optically active?

 

does it have to do something about R,S configurations? I have no idea, what it is...and how to know whether a molecule is optically active or not

 

thanks

Usually assymetric molecules rotate plane polarized light, so they are refered to as "optically active"

i remembered dr.feynmen said something about active molecules. It has a 2 percent possiblility on every rotation of the electron orbiting proton. And a T + V transaction between the R + T.

 

but later we discovered that electron do not go eliptical order or in circular path.

it all depends on what you mean by Opticaly Active?

 

if you`re talking photo-chemical (like Silver Chloride used in photography), then the light acts almost as a catalyst.

 

if you mean things that Fluorescent(sp), Phosphorescent(sp) or Laze then it`s to do with Ionisation levels.

 

things like LCD screens are different though, thats an electro-chem reaction, it aligns molecules in a polar fashion, to either allow existing light to pass or Not as the case may be.