Praseodymium (Pr)

Praseodymium properties

Atomic number

59

Atomic mass

140.91 u

Category

Lanthanide

Group

—

Period

6

Block

f-block

State at room temp.

Solid

Electronegativity

1.13

Melting point

1,208 K (934.8 °C)

Boiling point

3,793 K (3,519.8 °C)

Density

6.77 g/cm³

Valence electrons

2

Common charges

+3

Oxidation states

+3

Atomic radius

239 pm

Ionization energy

5.464 eV

Electron affinity

—

Radioactive

No, has stable isotopes

Discovered

1885

Praseodymium electron configuration

The electron configuration of Praseodymium (Pr) is [Xe] 4f3 6s2. Its 59 electrons are arranged in shells as 2, 8, 18, 21, 8, 2.

Protons, neutrons and electrons in Praseodymium

A neutral Praseodymium atom has 59 protons and 59 electrons. Most Praseodymium atoms have about 82 neutrons: the atomic mass rounded to 141, minus the atomic number 59.

Neutrons are approximate: atoms of the same element can have different numbers of neutrons (isotopes). Atomic number and mass

How many valence electrons does Praseodymium have?

2

Praseodymium has 2 valence electrons in its outermost shell. As an f-block element, its 4f or 5f electrons can also take part in bonding.

See every element: Periodic table with valence electrons

Praseodymium orbital diagram

Each box is an orbital that holds up to two electrons with opposite spins (↑↓). The inner shells are the same as the noble gas in brackets. How to write electron configurations

Molar mass of Praseodymium

140.91 g/mol

One mole of Praseodymium atoms (6.022 × 10²³ atoms) has a mass of 140.91 grams. Use this value to convert between grams and moles.

Praseodymium facts

• Its name means 'green twin', from the green color of its salts and its separation from didymium, whose name means 'twin'.
• Praseodymium metal slowly forms a green oxide coating in air, so it is usually stored under oil or in sealed containers.
• Praseodymium (Pr) has atomic number 59 and is a solid at room temperature. It was discovered in 1885.

Position in the periodic table

Praseodymium is element 59, in period 6 of the periodic table. It is one of the Lanthanides in the f-block, shown in the rows below the main table.

All lanthanides

Uses of Praseodymium

Praseodymium is mostly used together with neodymium in powerful permanent magnets for electric vehicle motors and wind turbines. It gives glass, ceramic glazes, and enamels a yellow-green color, and 'didymium' glass containing praseodymium and neodymium protects the eyes of glassblowers. It is also alloyed with magnesium to make strong, lightweight metals for aircraft engines.

Who discovered Praseodymium?

Austrian chemist Carl Auer von Welsbach discovered praseodymium in 1885 in Vienna, when he split a substance called didymium, long thought to be a single element, into two: praseodymium and neodymium.

Where does the name come from?

Praseodymium comes from the Greek prasios, 'leek green', and didymos, 'twin'. Carl Auer von Welsbach split didymium, the so-called twin of lanthanum, into two elements in 1885 and named this one for its green salts.

Discovery timeline