Mendelevium

Mendelevium is atom number 101 — every Mendelevium atom has exactly 101 protons in its center, and that number is what makes it Mendelevium and nothing else. Its symbol is Md. At room temperature it is a solid.

Mendelevium is a synthetic element with chemical symbol Md (formerly Mv) and atomic number 101. A metallic radioactive transuranic element in the actinide series, it is the first element that currently cannot be produced in macroscopic quantities through neutron bombardment of lighter elements. It is the antepenultimate actinide and the ninth transuranic element.

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

Mendelevium sits in period 7, group 3 of the f-block. Its 101 electrons fill shells of 2, 8, 18, 32, 31, 8, 2 — written as [Rn] 5f13 7s2. Its electronegativity is 1.3 on the Pauling scale, and pulling the first electron off takes 635 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 5f13
Ionization energies (kJ/mol): 635
Electron affinity: 93.91 kJ/mol · Electronegativity (Pauling): 1.3
Density: — · melts 1100 K · boils —

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