Berkelium

Berkelium is atom number 97 — every Berkelium atom has exactly 97 protons in its center, and that number is what makes it Berkelium and nothing else. Its symbol is Bk. At room temperature it is a solid.

Berkelium is a transuranic radioactive chemical element with symbol Bk and atomic number 97. It is a member of the actinide and transuranium element series. It is named after the city of Berkeley, California, the location of the University of California Radiation Laboratory where it was discovered in December 1949.

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

Berkelium sits in period 7, group 3 of the f-block. Its 97 electrons fill shells of 2, 8, 18, 32, 27, 8, 2 — written as [Rn] 5f9 7s2. Its electronegativity is 1.3 on the Pauling scale, and pulling the first electron off takes 601 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 5f9
Ionization energies (kJ/mol): 601
Electron affinity: -165.24 kJ/mol · Electronegativity (Pauling): 1.3
Density: 14.78 g/cm³ · melts 1259 K · boils 2900 K

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