Element 97 · Berkelium (Bk)

Berkelium Bohr model: diagram and electrons per shell

The berkelium Bohr model shows a berkelium atom (Bk) as a small nucleus with its electrons circling it in 7 shells: 2 in shell K, 8 in shell L, 18 in shell M, 32 in shell N, 27 in shell O, 8 in shell P and 2 in shell Q. This page has a rotating 3D berkelium Bohr model, a flat diagram, a table of the electrons in each shell and the steps to draw it yourself.

Rotate the berkelium Bohr model in 3D

Drag to orbit, scroll to zoom.

This is a Bohr model of berkelium (Bk), a simplified picture of a single berkelium atom. Its nucleus holds 97 protons, and a neutral berkelium atom has 97 electrons, arranged around it in 7 shells (2 in shell K, 8 in shell L, 18 in shell M, 32 in shell N, 27 in shell O, 8 in shell P and 2 in shell Q).

Bk K · 21s² L · 82s² 2p⁶ M · 183s² 3p⁶ 3d¹⁰ N · 324s² 4p⁶ 4d¹⁰ 4f¹⁴ O · 275s² 5p⁶ 5d¹⁰ 5f⁹ P · 86s² 6p⁶ Q · 27s²

Berkelium Bohr model diagram

Bohr model diagram of berkelium: a nucleus of 97 protons with 97 electrons on 7 shells, 2 in shell K, 8 in shell L, 18 in shell M, 32 in shell N, 27 in shell O, 8 in shell P and 2 in shell Q, each ring labelled with its shell letter. — The berkelium Bohr model drawn flat: each ring is a shell, labelled with its letter, and every dot is an electron (2 in shell K, 8 in shell L, 18 in shell M, 32 in shell N, 27 in shell O, 8 in shell P and 2 in shell Q).

Berkelium electrons per shell

A neutral berkelium atom has 97 electrons, one for each of its 97 protons. They fill the shells from the nucleus outwards: 2 in shell K, 8 in shell L, 18 in shell M, 32 in shell N, 27 in shell O, 8 in shell P and 2 in shell Q.

Electrons in each shell of the berkelium Bohr model
Shell	Shell number (n)	Electrons	Most it can hold (2n²)	Subshells
K	1	2	2	1s²
L	2	8	8	2s² 2p⁶
M	3	18	18	3s² 3p⁶ 3d¹⁰
N	4	32	32	4s² 4p⁶ 4d¹⁰ 4f¹⁴
O	5	27	50	5s² 5p⁶ 5d¹⁰ 5f⁹
P	6	8	72	6s² 6p⁶
Q	7	2	98	7s²

How the berkelium Bohr model builds up, shell by shell

Watch the berkelium Bohr model come together: the nucleus first, then each shell in turn, from the innermost outwards, with its electrons joining the ring. The legend names every shell and counts its electrons, so you can read off the arrangement (2 in shell K, 8 in shell L, 18 in shell M, 32 in shell N, 27 in shell O, 8 in shell P and 2 in shell Q) as it forms.

Animation of the berkelium Bohr model being built: a nucleus of 97 protons appears first, then each shell grows in around it and takes its electrons, giving 97 electrons on 7 shells (2 in shell K, 8 in shell L, 18 in shell M, 32 in shell N, 27 in shell O, 8 in shell P and 2 in shell Q). — The berkelium Bohr model built up in six seconds: the nucleus first, then each shell with its electrons, ending with 2 in shell K, 8 in shell L, 18 in shell M, 32 in shell N, 27 in shell O, 8 in shell P and 2 in shell Q. Protons are red, neutrons yellow and electrons blue.

How to draw the berkelium Bohr model

Find the atomic number. Berkelium has atomic number 97, so a neutral atom has 97 protons and 97 electrons.
Draw the nucleus. Put a circle in the centre and write Bk in it. The 97 protons sit there with the neutrons.
Draw the shells. Sketch 7 shells as rings around the nucleus. A shell holds at most 2n² electrons: 2 in the first, 8 in the second, 18 in the third and 32 in the fourth.
Place the electrons. Fill from the inside out: 2 in shell K, 8 in shell L, 18 in shell M, 32 in shell N, 27 in shell O, 8 in shell P and 2 in shell Q.
Check the total. 2 + 8 + 18 + 32 + 27 + 8 + 2 = 97, the atomic number, so every electron is accounted for.

Atomic data for the berkelium Bohr model

The numbers behind the berkelium Bohr model, grouped by topic. Radii are in picometres (pm) and energies in kilojoules per mole (kJ/mol).

Identity

Symbol: Bk
Atomic number: 97
Atomic mass: [247] u
Family: Actinides
Position: period 7 of the f-block
Block: f-block

Electron configuration

Full: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁶ 7s² 5f⁹
Shorthand: [Rn] 5f⁹ 7s²
Electrons per shell: 2, 8, 18, 32, 27, 8, 2
Outer-shell electrons: 2 in shell Q

Ionisation energies

I₁: 601

Energy to remove each electron in turn (kJ/mol). A sharp jump means the next electron comes from an inner shell.

Electronegativity and electron affinity

Electronegativity (Pauling): 1.3
Electron affinity (kJ/mol): -165.24

Oxidation states

Charges the element commonly takes in compounds.

Physical properties, abundance and history of berkelium

Bulk properties of berkelium, how common it is, who discovered it and some of its compounds.

Physical properties

Phase at room conditions: Solid
Appearance: Silvery
Melting point: 985.85°C (1259 K)
Boiling point: 2626.85°C (2900 K)
Density: 14.78 g/cm³

Discovery

Discovered by: Lawrence Berkeley National Laboratory
Year: 1949

Common compounds

Berkelium Bk
Berkelium-249 Bk
Berkelium, isotope of mass 247 Bk
Berkelium-250 Bk
Berkelium-245 Bk
Berkelium, isotope of mass 246 Bk
Berkelium(III) iodide BkI3-3
Berkelium(III) fluoride BkF3-3

Compounds listed in the PubChem database.

Main isotopes of berkelium

Isotopes of berkelium share the same 97 protons but differ in neutrons. Natural isotopes come first, then the longest-lived others.

Main isotopes of berkelium: mass number, abundance, half-life and decay
Mass number	Natural abundance	Half-life	Decay
243	–	4.6 h	β⁺, α
244	–	5.02 h	β⁺, α
245	–	4.95 d	EC, α
246	–	1.8 d	β⁺, α
247	–	1.38 ky	α, SF
249	–	327.2 d	β⁻, α, SF

α = alpha decay, β⁻ = beta-minus, β⁺ = beta-plus, EC = electron capture, SF = spontaneous fission, p / n = proton / neutron emission.

More about berkelium

Berkelium on the periodic table – properties, isotopes, uses and the full berkelium page.
Actinides – all actinide elements and their trends.
Bohr model of every element – the Bohr model of all 118 elements.