Periodic TableAll elementsRuthenium
No. 044
Ru
101.07 u
Element · Transition Metal

Ruthenium

Ruthenium (钌, symbol Ru) is chemical element number 44, a Transition Metal in period 5, group 8 of the periodic table, with a standard atomic weight of about 101.07. Rare, hard, white transition metal of the platinum group. Used in electronics and catalysis.

Period 5Group 8[Kr] 4d⁷ 5s¹

Properties

Atomic number44
SymbolRu
Atomic mass101.07 u
CategoryTransition Metal
Period5
Group8
Electron configuration[Kr] 4d⁷ 5s¹
Electronegativity2.2
Covalent radius146 pm
Density12.37 g/cm³
Melting point2607 K
Boiling point4423 K
DiscoveryKarl Ernst Claus, 1844

Overview

Rare, hard, white transition metal of the platinum group. Used in electronics and catalysis. Ruthenium (symbol Ru) is chemical element number 44, sitting in period 5, group 8 of the periodic table and classed as a Transition Metal. As a transition metal it commonly shows several oxidation states, forms coloured compounds, and is widely used in catalysts and alloys.

Its electron configuration is [Kr] 4d⁷ 5s¹, with 1 electron in the outer shell, and an electronegativity of about 2.2 (Pauling). Around 25 °C it is usually a solid (a very high melting point); it melts near 2607 K (2333.9 °C), boils near 4423 K (4149.9 °C), has a density around 12.37 g/cm³.

In industry and daily life it turns up in Catalysis, Electronics / Semiconductors and Precious Metal. It was first described by Karl Ernst Claus in 1844. The periodic trends guide explains the underlying patterns.

Electron shells

Ru44

Electrons per shell: 2 · 8 · 18 · 15 · 1

Main uses

Hazard

LowNo special hazard flags.

Compounds containing Ruthenium

No compounds in this knowledge base contain Ruthenium yet.

Data sources

Atomic mass uses IUPAC (CIAAW) standard atomic weights; the covalent radius is from Cordero et al. (2008). Verify on the RSC Periodic Table, PubChem and Wikipedia. Educational reference only.