Chlorine atoms strongly chemisorbed at dangling bond sites on the Si(1
00)-(2x1) surface are observed by scanning tunneling microscopy (STM)
to hop between adjacent sites. The origin of this behavior is suggeste
d to be an interaction between the field of the probe tip and the dipo
le moment of the silicon-chlorine bond. Chlorine atom migration is sho
wn to be facilitated by the presence of a metastable chlorine bridge-b
onded minimum. The STM probe was used to excite single chlorine atoms
into this bridging configuration, resulting in a local population inve
rsion. Selective application of voltage pulses between the probe tip a
nd the surface rearranged the local bonding and induced transformation
s between different types of chlorine sites. In this manner, adsorbed
species can be dissected and their composition and structure directly
probed.