Context: Right-clicking on an atom.

Duplicate: Takes a copy from the atom in context.

+ R-group attachment: gives an R-group attachment to the atom

- R-group attachment: removes an R-group attachment from the atom

Atom Properties: opens the Atom properties dialog window.

Absolute stereo (chiral)* : Sets the "Absolute" chiral flag on the entire structure, indicating that the molecule represents a single, well-defined stereoisomer.

*Absolute stereo flag is displayed only when the chiral flag visibility is turned on in View Settings dialog.