From Simple English Wikipedia, the free encyclopedia

Radon is a chemical element in the periodic table. It is element 86 on the periodic table and its symbol is Rn. It is an odorless, tasteless noble gas. It is quite radioactive and can decay very quickly. 27 isotopes of Radon are known today. The most stable of them has a half life of about 3.8 days.

Chemistry[change | change source]

Radon is a gas and is part of the group known as the noble gases. It does not react with other elements, so it is found pure. Radon is radioactive, meaning that it can give off harmful rays. Some people have high levels of radon in their houses, and this can be very dangerous. A lot of radon can get stuck in the basement of old houses, and so people end up breathing it in. It gets stuck in the lungs and has been known to cause cancer. There are groups that try to make sure there is no dangerous radon in houses.

It can occur naturally on the Earth but is a very small amount. As elements like Thorium and Uranium decay, some of that gets turned into Radon.

Radon can cause lung cancer and is the second most popular cause of lung cancer straight after smoking.

History[change | change source]

Radon was the fifth radioactive element to be discovered, in 1899 by Ernest Rutherford and Robert B. Owens at McGill University in Montreal, after uranium, thorium, radium, and polonium. In 1899, Pierre and Marie Curie saw that the gas given off by radium remained radioactive for a month. Later that year, Rutherford and Owens noticed different types of them when trying to measure radiation from thorium oxide.

Uses[change | change source]

It is sometimes used in radiation therapy. However, it is very dangerous to use.

An electron shell diagram for radon. Note the eight electrons in the outer shell.
Radon, 00Rn
Pronunciation/ˈrdɒn/ (RAY-don)
Appearancecolorless gas
Mass number[222]
Radon in the periodic table
Hydrogen Helium
Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon
Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon
Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton
Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon
Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury (element) Thallium Lead Bismuth Polonium Astatine Radon
Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson


Groupgroup 18 (noble gases)
Periodperiod 6
Block  p-block
Electron configuration[Xe] 4f14 5d10 6s2 6p6
Electrons per shell2, 8, 18, 32, 18, 8
Physical properties
Phase at STPgas
Melting point202 K ​(−71 °C, ​−96 °F)
Boiling point211.5 K ​(−61.7 °C, ​−79.1 °F)
Density (at STP)9.73 g/L
when liquid (at b.p.)4.4 g/cm3
Critical point377 K, 6.28 MPa[1]
Heat of fusion3.247 kJ/mol
Heat of vaporization18.10 kJ/mol
Molar heat capacity5R/2 = 20.786 J/(mol·K)
Vapor pressure
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K) 110 121 134 152 176 211
Atomic properties
Oxidation states0, +2, +6
ElectronegativityPauling scale: 2.2
Ionization energies
  • 1st: 1037 kJ/mol
Covalent radius150 pm
Van der Waals radius220 pm
Color lines in a spectral range
Spectral lines of radon
Other properties
Natural occurrencefrom decay
Crystal structureface-centered cubic (fcc)
Face-centered cubic crystal structure for radon
Thermal conductivity3.61×103  W/(m⋅K)
Magnetic orderingnon-magnetic
CAS Number10043-92-2
DiscoveryErnest Rutherford and Robert B. Owens (1899)
First isolationWilliam Ramsay and Robert Whytlaw-Gray (1910)
Isotopes of radon
Main isotopes[2] Decay
abun­dance half-life (t1/2) mode pro­duct
210Rn synth 2.4 h α 206Po
211Rn synth 14.6 h ε 211At
α 207Po
222Rn trace 3.8235 d α 218Po
224Rn synth 1.8 h β 224Fr
 Category: Radon
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Related pages[change | change source]

References[change | change source]

  1. Haynes, William M., ed. (2011). CRC Handbook of Chemistry and Physics (92nd ed.). Boca Raton, FL: CRC Press. p. 4.122. ISBN 1439855110.
  2. Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae.