It is its willingness to lose an electron completely and form a positively charge ion that makes caesium the most reactive metal in the periodic table, and yes I am including its relative francium!

Cesium is a metal in group IA of the periodic table with atomic number 55, an atomic weight of 132.905, and a density of 1.9 Mg/m 3. Its melting point is 28.7 C, and it boils at 690 C. The electronic ...

The periodic table can be read across from left to the ... The melting points then get gradually lower, with the element caesium four places down having a melting point of 28°C.

When Mendeleev first proposed his periodic table in 1869 he left gaps for elements not yet discovered, but that he predicted should exist. One such gap was one beneath caesium, a position later found ...