Radon (Rn)

Radon is a chemical element with symbol Rn and atomic number 86. It is a radioactive, colorless, odorless, tasteless noble gas first identified by Friedrich Ernst Dorn; later work by Ernest Rutherford and Robert B. Owens explored its properties and decay.

Atomic Number

86

Atomic Mass

222 u

Category

noble gas

Phase

gas

Density

0.00973 g/cm³

Electron Shells

2, 8, 18, 32, 18, 8

Atomic Structure

Protons: 86 • Electrons: 86 • Neutrons: Varies by isotope

Electron Configuration: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁶

Discovery

1900 • Friedrich Ernst Dorn