44 Ru 101.07

Ruthenium

Transition metal · Group 8 · Period 5

Ruthenium (symbol Ru, atomic number 44) is a hard platinum-group metal used in electronics and catalysis. It is classified as a transition metal and sits in group 8, period 5 of the periodic table.

Overview

Ruthenium is the chemical element with atomic number 44 and the symbol Ru. With a standard atomic weight of 101.07, it is a transition metal. In the periodic table it occupies group 8 and period 5, and under standard conditions it is normally a solid. Ruthenium is a hard platinum-group metal used in electronics and catalysis.

Atomic structure

An atom of Ruthenium has 44 protons in its nucleus and, when neutral, 44 electrons arranged in the configuration [Kr] 4d7 5s1. Its standard atomic weight of 101.07 reflects the natural mix of its stable isotopes.

Discovery and place in the table

Ruthenium was discovered in 1844 by Karl Ernst Claus. It follows Technetium (Tc) and precedes Rhodium (Rh) in order of atomic number.

Key properties of Ruthenium
Atomic number 44
Symbol Ru
Atomic mass 101.07
Category Transition metal
Group 8
Period 5
Electron configuration [Kr] 4d7 5s1
Phase at STP Solid
Discovered 1844 (Karl Ernst Claus)