radon: Quick Facts

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Last updated

Oct. 28, 2026

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Facts

Also Known As	Rn • niton • radium emanation

Photos

A labeled diagram of the periodic table entry for radon shows its atomic number 86, symbol Rn, atomic weight 222, electron configuration, and name. It is identified as a noble gas with a face-centered cubic crystal structure.

Diagram showing how radon gas can enter a home through cracks in the floor, slab joints, hollow-block walls, drains, and around water supply pipes.

Line graph showing the first ionization energies of the elements as a function of atomic number, with peaks at noble gases like helium, neon, argon, krypton, xenon, and radon, and labeled elements at key points.

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Topics

radon-222 radon-219 radon-220 chemical element noble gas hydrogen carbon sodium nitrogen sulfur phosphorus boron iodine fluorine zinc

Key People

William Ramsay

Sir William Ramsay

British chemist

Concept artwork on the periodic table of elements.

118 Names and Symbols of the Periodic Table Quiz

Periodic Table of the elements concept image (chemistry)

Facts You Should Know: The Periodic Table Quiz