Ruthenium (Ru)

Ruthenium properties

Atomic number

44

Atomic mass

101.07 u

Category

Transition metal

Group

8

Period

5

Block

d-block

State at room temp.

Solid

Electronegativity

2.2

Melting point

2,607 K (2,333.8 °C)

Boiling point

4,423 K (4,149.8 °C)

Density

12.45 g/cm³

Valence electrons

1

Common charges

+3

Oxidation states

+3

Atomic radius

207 pm

Ionization energy

7.361 eV

Electron affinity

1.05 eV

Radioactive

No, has stable isotopes

Discovered

1844

Ruthenium electron configuration

The electron configuration of Ruthenium (Ru) is [Kr] 4d7 5s1. Its 44 electrons are arranged in shells as 2, 8, 18, 15, 1.

Protons, neutrons and electrons in Ruthenium

A neutral Ruthenium atom has 44 protons and 44 electrons. Most Ruthenium atoms have about 57 neutrons: the atomic mass rounded to 101, minus the atomic number 44.

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

How many valence electrons does Ruthenium have?

1

Ruthenium has 1 valence electron, counting the electrons in its outermost s subshell. Like most transition metals, it can also use d electrons in bonding.

See every element: Periodic table with valence electrons

Ruthenium 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 Ruthenium

101.07 g/mol

One mole of Ruthenium atoms (6.022 × 10²³ atoms) has a mass of 101.07 grams. Use this value to convert between grams and moles.

Ruthenium facts

• Ruthenium was the last of the six platinum-group metals to be discovered.
• Its name comes from Ruthenia, a Latin name for Russia, the country where it was discovered.
• Ruthenium (Ru) has atomic number 44 and is a solid at room temperature. It was discovered in 1844.

Position in the periodic table

Ruthenium is element 44, in period 5 and group 8 of the periodic table, in the d-block.

All transition metals

Uses of Ruthenium

Ruthenium is used mainly in electronics: thin ruthenium layers help hard disk drives store more data, and ruthenium oxide is used in chip resistors. Small amounts harden platinum and palladium for wear-resistant electrical contacts. Ruthenium compounds are also important catalysts, including the Grubbs catalysts that chemists use to build complex molecules for medicines and plastics.

Who discovered Ruthenium?

Russian chemist Karl Ernst Claus discovered ruthenium in 1844 at Kazan University, while studying the residues left over after platinum had been extracted from ore from the Ural Mountains.

Where does the name come from?

Ruthenium comes from Ruthenia, a Latin name for Russia. Karl Klaus, who isolated the element at Kazan University in 1844, named it in honor of the country where he lived and worked.

Discovery timeline