Fermium

Fermium is atom number 100 — every Fermium atom has exactly 100 protons in its center, and that number is what makes it Fermium and nothing else. Its symbol is Fm. At room temperature it is a solid.

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.

Summary from the source dataset, derived from Wikipedia (CC BY-SA 3.0) · original article

Fermium sits in period 7, group 3 of the f-block. Its 100 electrons fill shells of 2, 8, 18, 32, 30, 8, 2 — written as [Rn] 5f12 7s2. Its electronegativity is 1.3 on the Pauling scale, and pulling the first electron off takes 627 kJ/mol. The outermost shell holds 2 electrons — the ones that do all the chemistry.

Full configuration: 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 7s2 5f12
Ionization energies (kJ/mol): 627
Electron affinity: 33.96 kJ/mol · Electronegativity (Pauling): 1.3
Density: — · melts 1800 K · boils —

Values exactly as published — see where the data comes from.