Element 84 · Polonium (Po)

Polonium Bohr model: diagram and electrons per shell

The polonium Bohr model shows a polonium atom (Po) as a small nucleus with its electrons circling it in 6 shells: 2 in shell K, 8 in shell L, 18 in shell M, 32 in shell N, 18 in shell O and 6 in shell P. This page has a rotating 3D polonium Bohr model, a flat diagram, a table of the electrons in each shell and the steps to draw it yourself.

Rotate the polonium Bohr model in 3D

Drag to orbit, scroll to zoom.

This is a Bohr model of polonium (Po), a simplified picture of a single polonium atom. Its nucleus holds 84 protons, and a neutral polonium atom has 84 electrons, arranged around it in 6 shells (2 in shell K, 8 in shell L, 18 in shell M, 32 in shell N, 18 in shell O and 6 in shell P).

Po K · 21s² L · 82s² 2p⁶ M · 183s² 3p⁶ 3d¹⁰ N · 324s² 4p⁶ 4d¹⁰ 4f¹⁴ O · 185s² 5p⁶ 5d¹⁰ P · 66s² 6p⁴

Polonium Bohr model diagram

Bohr model diagram of polonium: a nucleus of 84 protons with 84 electrons on 6 shells, 2 in shell K, 8 in shell L, 18 in shell M, 32 in shell N, 18 in shell O and 6 in shell P, each ring labelled with its shell letter. — The polonium 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, 18 in shell O and 6 in shell P).

Polonium electrons per shell

A neutral polonium atom has 84 electrons, one for each of its 84 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, 18 in shell O and 6 in shell P.

Electrons in each shell of the polonium 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	18	50	5s² 5p⁶ 5d¹⁰
P	6	6	72	6s² 6p⁴

How the polonium Bohr model builds up, shell by shell

Watch the polonium 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, 18 in shell O and 6 in shell P) as it forms.

Animation of the polonium Bohr model being built: a nucleus of 84 protons appears first, then each shell grows in around it and takes its electrons, giving 84 electrons on 6 shells (2 in shell K, 8 in shell L, 18 in shell M, 32 in shell N, 18 in shell O and 6 in shell P). — The polonium 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, 18 in shell O and 6 in shell P. Protons are red, neutrons yellow and electrons blue.

How to draw the polonium Bohr model

Find the atomic number. Polonium has atomic number 84, so a neutral atom has 84 protons and 84 electrons.
Draw the nucleus. Put a circle in the centre and write Po in it. The 84 protons sit there with the neutrons.
Draw the shells. Sketch 6 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, 18 in shell O and 6 in shell P.
Check the total. 2 + 8 + 18 + 32 + 18 + 6 = 84, the atomic number, so every electron is accounted for.

Atomic data for the polonium Bohr model

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

Identity

Symbol: Po
Atomic number: 84
Atomic mass: [209] u
Family: Post-Transition Metals
Position: group 16, period 6
Block: p-block

Electron configuration

Full: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁴
Shorthand: [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁴
Electrons per shell: 2, 8, 18, 32, 18, 6
Outer-shell electrons: 6 in shell P

Ionisation energies

I₁: 812.1

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

Atomic radii

Calculated (pm): 135
Empirical (pm): 190
Covalent (pm): 145
Van der Waals (pm): 197

Electronegativity and electron affinity

Electronegativity (Pauling): 2
Electron affinity (kJ/mol): 136

Oxidation states

−2 +2 +4

Charges the element commonly takes in compounds.

Physical properties, abundance and history of polonium

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

Physical properties

Phase at room conditions: Solid
Appearance: Silvery
Melting point: 253.85°C (527 K)
Boiling point: 961.85°C (1235 K)
Density: 9.196 g/cm³
Molar heat capacity (J/mol·K): 26.4
Heat of fusion (kJ/mol): 10
Heat of vaporisation (kJ/mol): 102.9

Abundance

Earth's crust (mg/kg): 0
Oceans (mg/L): 0

Discovery

Discovered by: Pierre Curie
Year: 1898

Common compounds

Polonium-210 Po
Polonium Po
Polonium tetrachloride Cl4Po
Polonium tetranitrate N4O12Po-4
Polonium, isotope of mass 207 Po
Polonium, isotope of mass 203 Po
Polonium, isotope of mass 205 Po
Polonium hydride (PoH2) H2Po

Compounds listed in the PubChem database.

Main isotopes of polonium

Isotopes of polonium share the same 84 protons but differ in neutrons. Natural isotopes come first, then the longest-lived others.

Main isotopes of polonium: mass number, abundance, half-life and decay
Mass number	Natural abundance	Half-life	Decay
204	–	3.519 h	β⁺, α
206	–	8.8 d	β⁺, α
207	–	5.8 h	β⁺, α
208	–	2.898 y	α, β⁺
209	–	124 y	α, β⁺
210	–	138.376 d	α

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

More about polonium

Polonium on the periodic table – properties, isotopes, uses and the full polonium page.
Post-Transition Metals – all post-transition metal elements and their trends.
Bohr model of every element – the Bohr model of all 118 elements.