#97 / 118
97Bk[247]
Actinidessolid at STPF-block

Berkelium

Group: f-block•Period: 7•Standard Atomic Weight: [247] u
Open Full Periodic TableView Bohr Model

Why is Berkelium in this position?

Understanding the scientific rationale behind Berkelium's position in the periodic table:

Group Assignment
Group Lanthanide / Actinide

Actinide series element filling the 5f subshell.

Period Assignment
Period 7

Belongs to Period 7 because its outermost electrons occupy n=7.

Orbital Block
F-block

Belongs to the f-block because valence electrons fill 5f orbitals (5f⁹ 7s²).

Chemical Category
Actinides

Classified as an actinide radioactive synthetic metal.

Atomic Structure & Bohr Shell Model

Shell Distribution: [2, 8, 18, 32, 27, 8, 2]

Bohr Atomic Shell Model(2, 8, 18, 32, 27, 8, 2)

Hover or tap any shell orbit ring to inspect electron counts and 2n² capacities.

97 Protons (p⁺)150 Neutrons (n⁰)
KShell K: Electron 1 of 2Shell K: Electron 2 of 2LShell L: Electron 1 of 8Shell L: Electron 2 of 8Shell L: Electron 3 of 8Shell L: Electron 4 of 8Shell L: Electron 5 of 8Shell L: Electron 6 of 8Shell L: Electron 7 of 8Shell L: Electron 8 of 8MShell M: Electron 1 of 18Shell M: Electron 2 of 18Shell M: Electron 3 of 18Shell M: Electron 4 of 18Shell M: Electron 5 of 18Shell M: Electron 6 of 18Shell M: Electron 7 of 18Shell M: Electron 8 of 18Shell M: Electron 9 of 18Shell M: Electron 10 of 18Shell M: Electron 11 of 18Shell M: Electron 12 of 18Shell M: Electron 13 of 18Shell M: Electron 14 of 18Shell M: Electron 15 of 18Shell M: Electron 16 of 18Shell M: Electron 17 of 18Shell M: Electron 18 of 18NShell N: Electron 1 of 32Shell N: Electron 2 of 32Shell N: Electron 3 of 32Shell N: Electron 4 of 32Shell N: Electron 5 of 32Shell N: Electron 6 of 32Shell N: Electron 7 of 32Shell N: Electron 8 of 32Shell N: Electron 9 of 32Shell N: Electron 10 of 32Shell N: Electron 11 of 32Shell N: Electron 12 of 32Shell N: Electron 13 of 32Shell N: Electron 14 of 32Shell N: Electron 15 of 32Shell N: Electron 16 of 32Shell N: Electron 17 of 32Shell N: Electron 18 of 32Shell N: Electron 19 of 32Shell N: Electron 20 of 32Shell N: Electron 21 of 32Shell N: Electron 22 of 32Shell N: Electron 23 of 32Shell N: Electron 24 of 32Shell N: Electron 25 of 32Shell N: Electron 26 of 32Shell N: Electron 27 of 32Shell N: Electron 28 of 32Shell N: Electron 29 of 32Shell N: Electron 30 of 32Shell N: Electron 31 of 32Shell N: Electron 32 of 32OShell O: Electron 1 of 27Shell O: Electron 2 of 27Shell O: Electron 3 of 27Shell O: Electron 4 of 27Shell O: Electron 5 of 27Shell O: Electron 6 of 27Shell O: Electron 7 of 27Shell O: Electron 8 of 27Shell O: Electron 9 of 27Shell O: Electron 10 of 27Shell O: Electron 11 of 27Shell O: Electron 12 of 27Shell O: Electron 13 of 27Shell O: Electron 14 of 27Shell O: Electron 15 of 27Shell O: Electron 16 of 27Shell O: Electron 17 of 27Shell O: Electron 18 of 27Shell O: Electron 19 of 27Shell O: Electron 20 of 27Shell O: Electron 21 of 27Shell O: Electron 22 of 27Shell O: Electron 23 of 27Shell O: Electron 24 of 27Shell O: Electron 25 of 27Shell O: Electron 26 of 27Shell O: Electron 27 of 27PShell P: Electron 1 of 8Shell P: Electron 2 of 8Shell P: Electron 3 of 8Shell P: Electron 4 of 8Shell P: Electron 5 of 8Shell P: Electron 6 of 8Shell P: Electron 7 of 8Shell P: Electron 8 of 8QShell Q: Electron 1 of 2Shell Q: Electron 2 of 2BkZ = 97

Educational Note: This Niels Bohr planetary model visually illustrates principal quantum energy shells ($n=1, 2, 3\dots$) and electron counts. In modern quantum mechanics (Schrödinger model), electrons do not orbit in fixed circular planetary tracks, but exist as 3D probability clouds (orbitals: $s, p, d, f$) governed by the Heisenberg uncertainty principle.

Electron Shell Filling Breakdown

Shell K (n=1):2 / 2 electrons (100%)
Shell L (n=2):8 / 8 electrons (100%)
Shell M (n=3):18 / 18 electrons (100%)
Shell N (n=4):32 / 32 electrons (100%)
Shell O (n=5):27 / 50 electrons (54%)
Shell P (n=6):8 / 72 electrons (11%)
Shell Q (n=7):2 / 98 electrons (2%)
Aufbau Electron Configuration
1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d¹⁰ 5f⁹ 6s² 6p⁶ 7s²

Neutral ground state configuration. Valence electrons: 11.

Atomic & Quantum Properties

Electronegativity (Pauling)1.3 Pauling
1st Ionization Energy601 kJ/mol
Electron Affinity-46 kJ/mol
Atomic Radius (empirical)167 pm
Common Oxidation States+3, +4
Crystal StructureDouble HCP

Physical & Thermal Properties

Density at STP14.78 g/cm³
Melting Point986 °C (1259 K)
Boiling Point2627 °C (2900 K)
Magnetic OrderingParamagnetic
Discovery Year1949
Discovered ByStanley G. Thompson, Albert Ghiorso & Glenn T. Seaborg

Real-World Uses, Occurrence & Compounds

Major Industrial & Everyday Uses
  • Target material for particle accelerators synthesizing superheavy elements (Tennessine discovery in 2010)
  • High-energy nuclear chemistry and transuranic crystal structure research
Occurrence in Nature

Synthesized in milligram quantities exclusively in specialized high-flux nuclear reactors (HFIR at Oak Ridge).

Etymology & Name Origin

Named after the city of Berkeley, California, where it was discovered at UC Berkeley

Important Chemical Compounds
BkO₂ (Berkelium dioxide)
BkCl₃ (Berkelium trichloride)
Interesting Chemical Facts
  • • In 2009, Oak Ridge National Laboratory spent months producing 22 milligrams of pure Berkelium-249, which was flown to Russia to synthesize element 117 (Tennessine).
  • • Berkelium was named after the city of Berkeley, California, paralleling its lanthanide twin Terbium named after Ytterby, Sweden.
  • • Less than one gram of berkelium has ever been produced since its discovery in 1949.
Safety & Handling Note

Intensely radioactive beta/alpha emitter; hazardous bioaccumulative heavy metal.

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