Rhenium

Rhenium is atom number 75 — every Rhenium atom has exactly 75 protons in its center, and that number is what makes it Rhenium and nothing else. Its symbol is Re. At room temperature it is a solid.

Rhenium is a chemical element with symbol Re and atomic number 75. It is a silvery-white, heavy, third-row transition metal in group 7 of the periodic table. With an estimated average concentration of 1 part per billion (ppb), rhenium is one of the rarest elements in the Earth's crust.

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

Rhenium sits in period 6, group 7 of the d-block. Its 75 electrons fill shells of 2, 8, 18, 32, 13, 2 — written as [Xe] 4f14 5d5 6s2. Its electronegativity is 1.9 on the Pauling scale, and pulling the first electron off takes 760 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 5d5
Ionization energies (kJ/mol): 760, 1260, 2510, 3640
Electron affinity: 5.8273 kJ/mol · Electronegativity (Pauling): 1.9
Density: 21.02 g/cm³ · melts 3459 K · boils 5869 K

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