Element 59 · Praseodymium (Pr)

Praseodymium Bohr model: diagram and electrons per shell

The praseodymium Bohr model shows a praseodymium atom (Pr) as a small nucleus with its electrons circling it in 6 shells: 2 in shell K, 8 in shell L, 18 in shell M, 21 in shell N, 8 in shell O and 2 in shell P. This page has a rotating 3D praseodymium Bohr model, a flat diagram, a table of the electrons in each shell and the steps to draw it yourself.

Rotate the praseodymium Bohr model in 3D

Drag to orbit, scroll to zoom.

This is a Bohr model of praseodymium (Pr), a simplified picture of a single praseodymium atom. Its nucleus holds 59 protons, and a neutral praseodymium atom has 59 electrons, arranged around it in 6 shells (2 in shell K, 8 in shell L, 18 in shell M, 21 in shell N, 8 in shell O and 2 in shell P).

Pr K · 21s² L · 82s² 2p⁶ M · 183s² 3p⁶ 3d¹⁰ N · 214s² 4p⁶ 4d¹⁰ 4f³ O · 85s² 5p⁶ P · 26s²

Praseodymium Bohr model diagram

Bohr model diagram of praseodymium: a nucleus of 59 protons with 59 electrons on 6 shells, 2 in shell K, 8 in shell L, 18 in shell M, 21 in shell N, 8 in shell O and 2 in shell P, each ring labelled with its shell letter. — The praseodymium 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, 21 in shell N, 8 in shell O and 2 in shell P).

Praseodymium electrons per shell

A neutral praseodymium atom has 59 electrons, one for each of its 59 protons. They fill the shells from the nucleus outwards: 2 in shell K, 8 in shell L, 18 in shell M, 21 in shell N, 8 in shell O and 2 in shell P.

Electrons in each shell of the praseodymium 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	21	32	4s² 4p⁶ 4d¹⁰ 4f³
O	5	8	50	5s² 5p⁶
P	6	2	72	6s²

How the praseodymium Bohr model builds up, shell by shell

Watch the praseodymium 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, 21 in shell N, 8 in shell O and 2 in shell P) as it forms.

Animation of the praseodymium Bohr model being built: a nucleus of 59 protons appears first, then each shell grows in around it and takes its electrons, giving 59 electrons on 6 shells (2 in shell K, 8 in shell L, 18 in shell M, 21 in shell N, 8 in shell O and 2 in shell P). — The praseodymium 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, 21 in shell N, 8 in shell O and 2 in shell P. Protons are red, neutrons yellow and electrons blue.

How to draw the praseodymium Bohr model

Find the atomic number. Praseodymium has atomic number 59, so a neutral atom has 59 protons and 59 electrons.
Draw the nucleus. Put a circle in the centre and write Pr in it. The 59 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, 21 in shell N, 8 in shell O and 2 in shell P.
Check the total. 2 + 8 + 18 + 21 + 8 + 2 = 59, the atomic number, so every electron is accounted for.

Atomic data for the praseodymium Bohr model

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

Identity

Symbol: Pr
Atomic number: 59
Atomic mass: 140.9077 u
Family: Lanthanides
Position: period 6 of the f-block
Block: f-block

Electron configuration

Full: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f³
Shorthand: [Xe] 4f³ 6s²
Electrons per shell: 2, 8, 18, 21, 8, 2
Outer-shell electrons: 2 in shell P

Ionisation energies

I₁: 527
I₂: 1020
I₃: 2086
I₄: 3761
I₅: 5551

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): 247
Empirical (pm): 185
Covalent (pm): 176

Electronegativity and electron affinity

Electronegativity (Pauling): 1.13
Electron affinity (kJ/mol): 93

Oxidation states

Charges the element commonly takes in compounds.

Physical properties, abundance and history of praseodymium

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

Physical properties

Phase at room conditions: Solid
Appearance: Grayish white
Melting point: 934.85°C (1208 K)
Boiling point: 3129.85°C (3403 K)
Density: 6.77 g/cm³
Thermal conductivity (W/m·K): 12.5
Specific heat (J/g·K): 0.193
Molar heat capacity (J/mol·K): 27.2
Heat of fusion (kJ/mol): 11.3
Heat of vaporisation (kJ/mol): 331

Abundance

Earth's crust (mg/kg): 9.2
Oceans (mg/L): 0

Discovery

Discovered by: Carl Auer von Welsbach
Year: 1885

Common compounds

Praseodymium Pr
Praseodymium acetate C6H9O6Pr
Praseodymium chloride Cl3Pr
Praseodymium fluoride (PrF3) F3Pr
Praseodymium(III) nitrate hexahydrate H12N3O15Pr
Praseodymium iodide (PrI3) I3Pr
Praseodymium nitride (PrN) NPr
Nitric acid, praseodymium(3+) salt (3:1) H3N3O9Pr

Compounds listed in the PubChem database.

Main isotopes of praseodymium

Isotopes of praseodymium share the same 59 protons but differ in neutrons. Natural isotopes come first, then the longest-lived others.

Main isotopes of praseodymium: mass number, abundance, half-life and decay
Mass number	Natural abundance	Half-life	Decay
137	–	1.28 h	β⁺
139	–	4.41 h	β⁺
141	100 %	stable	–
142	–	19.12 h	β⁻, EC
143	–	13.57 d	β⁻
145	–	5.984 h	β⁻

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

More about praseodymium

Praseodymium on the periodic table – properties, isotopes, uses and the full praseodymium page.
Lanthanides – all lanthanide elements and their trends.
Bohr model of every element – the Bohr model of all 118 elements.