Element 98 · Californium (Cf)

Californium Bohr model: diagram and electrons per shell

The californium Bohr model shows a californium atom (Cf) 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, 28 in shell O, 8 in shell P and 2 in shell Q. This page has a rotating 3D californium Bohr model, a flat diagram, a table of the electrons in each shell and the steps to draw it yourself.

Rotate the californium Bohr model in 3D

Drag to orbit, scroll to zoom.

This is a Bohr model of californium (Cf), a simplified picture of a single californium atom. Its nucleus holds 98 protons, and a neutral californium atom has 98 electrons, arranged around it in 7 shells (2 in shell K, 8 in shell L, 18 in shell M, 32 in shell N, 28 in shell O, 8 in shell P and 2 in shell Q).

Cf K · 21s² L · 82s² 2p⁶ M · 183s² 3p⁶ 3d¹⁰ N · 324s² 4p⁶ 4d¹⁰ 4f¹⁴ O · 285s² 5p⁶ 5d¹⁰ 5f¹⁰ P · 86s² 6p⁶ Q · 27s²

Californium Bohr model diagram

Bohr model diagram of californium: a nucleus of 98 protons with 98 electrons on 7 shells, 2 in shell K, 8 in shell L, 18 in shell M, 32 in shell N, 28 in shell O, 8 in shell P and 2 in shell Q, each ring labelled with its shell letter. — The californium 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, 28 in shell O, 8 in shell P and 2 in shell Q).

Californium electrons per shell

A neutral californium atom has 98 electrons, one for each of its 98 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, 28 in shell O, 8 in shell P and 2 in shell Q.

Electrons in each shell of the californium 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	28	50	5s² 5p⁶ 5d¹⁰ 5f¹⁰
P	6	8	72	6s² 6p⁶
Q	7	2	98	7s²

How the californium Bohr model builds up, shell by shell

Watch the californium 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, 28 in shell O, 8 in shell P and 2 in shell Q) as it forms.

Animation of the californium Bohr model being built: a nucleus of 98 protons appears first, then each shell grows in around it and takes its electrons, giving 98 electrons on 7 shells (2 in shell K, 8 in shell L, 18 in shell M, 32 in shell N, 28 in shell O, 8 in shell P and 2 in shell Q). — The californium 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, 28 in shell O, 8 in shell P and 2 in shell Q. Protons are red, neutrons yellow and electrons blue.

How to draw the californium Bohr model

Find the atomic number. Californium has atomic number 98, so a neutral atom has 98 protons and 98 electrons.
Draw the nucleus. Put a circle in the centre and write Cf in it. The 98 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, 28 in shell O, 8 in shell P and 2 in shell Q.
Check the total. 2 + 8 + 18 + 32 + 28 + 8 + 2 = 98, the atomic number, so every electron is accounted for.

Atomic data for the californium Bohr model

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

Identity

Symbol: Cf
Atomic number: 98
Atomic mass: [251] 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 5f¹⁰
Shorthand: [Rn] 5f¹⁰ 7s²
Electrons per shell: 2, 8, 18, 32, 28, 8, 2
Outer-shell electrons: 2 in shell Q

Ionisation energies

I₁: 608

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): -97.31

Oxidation states

Charges the element commonly takes in compounds.

Physical properties, abundance and history of californium

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

Physical properties

Phase at room conditions: Solid
Appearance: Silvery
Melting point: 899.85°C (1173 K)
Boiling point: 1469.85°C (1743 K)
Density: 15.1 g/cm³

Discovery

Discovered by: Lawrence Berkeley National Laboratory
Year: 1950

Common compounds

Californium Cf
Californium, isotope of mass 249 Cf
Californium-252 Cf
Californium-250 Cf
Californium-246 Cf
Californium, isotope of mass 253 Cf
Californium-248 Cf
(~251~Cf)Californium Cf

Compounds listed in the PubChem database.

Main isotopes of californium

Isotopes of californium share the same 98 protons but differ in neutrons. Natural isotopes come first, then the longest-lived others.

Main isotopes of californium: mass number, abundance, half-life and decay
Mass number	Natural abundance	Half-life	Decay
248	–	333.5 d	α, SF
249	–	351 y	α, SF
250	–	13.08 y	α, SF
251	–	898 y	α, SF
252	–	2.645 y	α, SF
254	–	60.5 d	SF, α, 2β⁻

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

More about californium

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