To create Mapping: 1. Select "Map reaction" tool in the Reaction group 2. Click on one atom on the reactant side 3. Click on mapped atom on the product side To remove a mapped atom: 1. Select "Map reaction" tool in the Reaction group 2. Click on the mapped atom on either reactant side or product side To Remove all mapped atoms: 1. Select "Clear reaction map" ubbton in the Reaction group.