Radon

Koushik 26/06/2026 19:58:09 Updated 26/06/2026 19:58:09

Property	Value
Atomic Number	86
Element	Radon
Symbol	Rn
Atomic Mass	[222] (most stable isotope)
Number of Neutrons	136 (Radon-222)
Number of Protons	86
Number of Electrons	86
Period	6
Group	18
Phase	Gas
Radioactive	Yes
Natural	Yes (from decay of uranium and thorium)
Metal	No
Nonmetal	Yes
Metalloid	No
Type	Noble Gas
Atomic Radius	120 pm (estimated)
Electronegativity	2.20 (Pauling scale, estimated)
First Ionization Energy	10.748 eV
Density	0.00973 g/cm³
Melting Point	−71 °C
Boiling Point	−61.7 °C
Number of Isotopes	No stable isotopes (Rn-222 most notable)
Discoverer	Friedrich Ernst Dorn
Year	1900
Specific Heat	0.094 J/g·K
Number of Shells	6
Number of Valence Electrons	8