Here you can switch on and off these elements.
If you have switched this on, you have field in the toobar where you can directly enter SMILES/InChI/CAS strings See Insert for details..
Enlarges the structure(s) painted.
Scales down the structure(s) painted.
Zooms to the original size.
Here you can enter some propeties (e. g. if atom numbers shall be drawn) which determine the look of the molecule.