58 Ce 140.12

Cerium

Lanthanide · Group — · Period 6

Cerium (symbol Ce, atomic number 58) is the most abundant rare-earth metal, used in catalytic converters and polishing powders. It is classified as a lanthanide and sits in the lanthanide series (f-block), period 6 of the periodic table.

Overview

Cerium is the chemical element with atomic number 58 and the symbol Ce. With a standard atomic weight of 140.12, it is a lanthanide. In the periodic table it occupies the lanthanide series (f-block) and period 6, and under standard conditions it is normally a solid. Cerium is the most abundant rare-earth metal, used in catalytic converters and polishing powders.

Atomic structure

An atom of Cerium has 58 protons in its nucleus and, when neutral, 58 electrons arranged in the configuration [Xe] 4f1 5d1 6s2. Its standard atomic weight of 140.12 reflects the natural mix of its stable isotopes.

Discovery and place in the table

Cerium was discovered in 1803 by Martin Heinrich Klaproth, Jöns Jacob Berzelius. It follows Lanthanum (La) and precedes Praseodymium (Pr) in order of atomic number.

Key properties of Cerium
Atomic number 58
Symbol Ce
Atomic mass 140.12
Category Lanthanide
Group
Period 6
Electron configuration [Xe] 4f1 5d1 6s2
Phase at STP Solid
Discovered 1803 (Martin Heinrich Klaproth, Jöns Jacob Berzelius)