A unique attribute of the scanning tunneling microscope (STM) is that
it provides a real space view of the atomic landscape of the system
under study. In addition, manipulation, spectroscopy, and chemical
modification on single molecules are possible. The ability to probe
individual atoms and molecules has made it possible to reveal properties
with otherwise would be hidden in the study of an ensemble of atoms and
molecules. These studies provide the basis for potential futuristic
applications in areas such as molecular electronics, chemical catalysis,
and nano-devices. Furthermore they prove that the STM is a unique tool
for measurement of quantum properties on nanostructures. I will present
some novel properties obtained from single molecules, intermolecular
interaction, and catalytic reaction pathways of oxygen atoms and
molecules with carbon monoxide on the surface with single molecule
resolution.