86 Rn 222

Radon

Noble Gas

Radon (Rn) is a chemical element with atomic number 86, classified as a noble gas. At room temperature it is a gas. It was discovered in 1900 by Friedrich Ernst Dorn.

Properties

Atomic number
86
Atomic mass
222 u
Category
Noble Gas
Group
18
Period
6
Block
p-block
Electron configuration
[Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁶
Phase at STP
Gas
Density
9.73 g/L
Melting point
202 K (-71.1 °C)
Boiling point
211.3 K (-61.8 °C)
Electronegativity
2.2
Atomic radius
120 pm
Ionization energy
10.749 eV
Discovery
1900 · Friedrich Ernst Dorn

Common uses

Cancer treatment, earthquake prediction, research

Did you know?

Radioactive noble gas that can accumulate in basements and cause cancer.