Fermium is a synthetic element with symbol Fm and atomic number 100. It is a member of the actinide series. It is the heaviest element that can be formed by neutron bombardment of lighter elements, and hence the last element that can be prepared in macroscopic quantities, although pure fermium metal has not yet been prepared.

Atomic Weight: 257
Density        42.42 g/cm^3.
Melting Point: 42.32
Boiling Point: 4.232