Francium is located on the seventh row of the first column in the periodic table of elements. Its appearance is unknown. It has a melting point of 21 degrees Celsius. Francium is slightly less reactive than Cesium. The reason for this is related to relativity. When heavier atoms have increasing numbers of protons and electrons, the electrons have to move continually faster since there are so many layers. The laws of relativity would have to be so that the electrons have slightly less mass, and they are also packed tighter around the nucleus. This makes them harder to remove and therefore less reactive. All of Francium's isotopes are radioactive, thus making Francium a very rare element. Francium 223, and 221 are the only naturally occurring isotopes through the decay chains of other atoms.