Palladium

Palladium is atom number 46 — every Palladium atom has exactly 46 protons in its center, and that number is what makes it Palladium and nothing else. Its symbol is Pd. At room temperature it is a solid.

Palladium is a chemical element with symbol Pd and atomic number 46. It is a rare and lustrous silvery-white metal discovered in 1803 by William Hyde Wollaston. He named it after the asteroid Pallas, which was itself named after the epithet of the Greek goddess Athena, acquired by her when she slew Pallas.

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

Palladium sits in period 5, group 10 of the d-block. Its 46 electrons fill shells of 2, 8, 18, 18 — written as [Kr] 4d10. Its electronegativity is 2.2 on the Pauling scale, and pulling the first electron off takes 804.4 kJ/mol. The outermost shell holds 18 electrons — the ones that do all the chemistry.

Full configuration: 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 4d10
Ionization energies (kJ/mol): 804.4, 1870, 3177
Electron affinity: 54.24 kJ/mol · Electronegativity (Pauling): 2.2
Density: 12.023 g/cm³ · melts 1828.05 K · boils 3236 K

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