Things zoom around pretty fast in the sub-atomic world. This is especially with one of the lightest particles, the electron:). All chemical reactions depend on the speed with which an electron makes a transition from one atom to another, and therefore timing such a transition is of extraordinary importance if one were to understand the processes in play behind a chemical reaction. Such research could help develop new catalysts, and also provide a boost to the relatively new field of spintronics.

Electron Cloud (Courtesy: University of Guelph)
Wilfried Wurth, a physicist from the University of Hamburg, Germany, and his team used short X-Ray pulses to watch an electron moving away from a Sulphur atom stuck to a Ruthenium metal surface. The electron took just 320 quintillionths of a second (320x10^-18 seconds) for the jump:D!
Quantum Mechanics makes it very tricky to observe such transitions. Electrons are not really point particles, but are smeared over a region of space. These regions can be viewed as clouds, and the goal therefore is to track these clouds.
The team used X-Rays to boost the energy of an electron close to the core of a Sulphur atom. This pushed the electron towards the Ruthenium surface, leaving the remaining electrons in the Sulphur atom to shuffle around. By watching how the X-Ray pulses were absorbed, the researchers tracked how long it took for the electron's cloud of probability to shift entirely from the Sulphur to the Ruthenium:):).