Radon Chemical Properties (25 Facts You Should Know)

Rn or Radon is a radioactive noble gas that is colorless and odorless like other inert gas. Let us talk about radon in this article.

The radioactive decay of thorium and uranium leads to the formation of radon and the half-life of the element is very short. Radon is the intermediate decay product of radium. The radioactive radon can form lead, polonium, and bismuth isotopes having lower stability.

In this article, we will discuss some basic information about radon like its position in the periodic table, chemical properties like melting and boiling point, isotopes, ionization energy, and many related facts.

1. Radon symbol

The atomic symbol of Radon is “Rn”.

Radon Atomic Symbol

2. Radon group in the periodic table

The group of Radon in the periodic table is 18 because it is a noble gas.

3. Radon period in the periodic table

Radon belongs to period 6 in the periodic table because it has more than 54 electrons in the valence shell.

4. Radon block in the periodic table

Radon is a p-block element because the valence electrons are present in the p orbital.

5. Radon atomic number

The atomic number of Radon is 86, which means it has 86 protons and 86 electrons because the number of protons is always equal to the number of electrons.

6. Radon atomic Weight

The atomic weight of Radon is 222 on the 12C scale which means the weight of Radon is the 222/12th part of the weight of the carbon element.

7. Radon Electronegativity according to Pauling

The electronegativity of Radon is 2.2 according to the Pauling scale, which means it has electronegative nature and can attract electrons toward itself.

8. Radon atomic Density

The atomic density of Radon is 9.73 g/cm3 which can be calculated by dividing the mass of Radon by its volume.

  • Density is calculated by the formula, atomic density = atomic mass / atomic volume.
  • The atomic mass or weight of Radon is 222 g
  • The volume of the Radon molecule is 22.4 liter at STP as per Avogardo’s calculation
  • So, the atomic density of Radon is, 222/ (22.4) = 9.91 g/cm3

9. Radon melting point

The melting point of Radon is -710C or 202K temperature because at room temperature Radon exists in gaseous form.

10. Radon boiling point

The boiling point of Radon is -61.70C or 211.3K.

11. Radon Van der Waals radius

The Van der Waal’s radius of Radon is 200 pm.

12. Radon ionic radius

The ionic radius of Radon is 200 pm which is the same as the covalent radius because for Radon the cation and anion are the same and it is not an ionic molecule. Rather, it forms by the covalent interaction between two Radon atoms.

13. Radon isotopes

Elements having the same number of electrons but different mass numbers are called isotopes of the original element. Let us discuss the isotopes of Radon.

Although Radon is inert it has 49 isotopes due to its radioactive nature which are listed below-

  • 195Rn
  • 195mRn
  • 196Rn
  • 197Rn
  • 197mRn
  • 198Rn
  • 199Rn
  • 199mRn
  • 200Rn
  • 201Rn
  • 201mRn
  • 202Rn
  • 203Rn
  • 203mRn
  • 204Rn
  • 205Rn
  • 206Rn
  • 207Rn
  • 207mRn
  • 208Rn
  • 209Rn
  • 209m1Rn
  • 209m2Rn
  • 210Rn
  • 210m1Rn
  • 210m2Rn
  • 210m3Rn
  • 211Rn
  • 212Rn
  • 213Rn
  • 214Rn
  • 214mRn
  • 215Rn
  • 216Rn
  • 217Rn
  • 218Rn
  • 219Rn
  • 220Rn
  • 221Rn
  • 222Rn
  • 223Rn
  • 224Rn
  • 225Rn
  • 226Rn
  • 227Rn
  • 228Rn
  • 229Rn
  • 230Rn
  • 231Rn

There are only 4 isotopes that are stable among the 49 isotopes of Radon which are discussed below –

No. of
210RnSynthetic2.4 hα124
211RnSynthetic14.6 h€, α125
222Rntrace3.82 dα136
224RnSynthetic1.8 hβ138
Isotopes of Radon

14. Radon electronic shell

The shell surrounding the nucleus as per principal quantum number and holding the electrons is called an electronic shell. Let us discuss the electronic shell of Radon.

The electronic shell distribution of Radon is 2 8 18 32 18 8 because it has s, p, d, and f orbitals around the nucleus.

15. Radon electron configurations

The electronic configuration of Radon is 1s2 2s2 2p6 3s2 3p3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 6s2 6p6 because it has 86 electrons and those electrons should be placed to the nearest orbital of the nucleus s, p, d, and f orbitals and for the 1st,2nd, 3rd, 4th, 5th, and 6th orbitals.

16. Radon energy of first ionization

The first ionization value for Radon is 1037 KJ/mol because the electron is removed from the fully-filled 6p orbital.

17. Radon energy of second ionization

The 2nd ionization energy of Radon is 2108 KJ/mol.

18. Radon energy of third ionization

The third ionization energy for Radon is 3304 KJ/mol because the third ionization occurs from 6p orbital and gets stabilization due to being half-filled but the value is higher than expected because

  • Rn has also a 5d orbital which is subject to poor shielding effect and for this reason, nucleus attraction force on the outer electrons will increase and the removal of the electron requires a larger amount of energy.
  • The 6s and 4s orbital of Rn has a strong shielding effect.

19. Radon oxidation states

The stable oxidation of Rn is O as it is noble gas so it has a filled valence orbital but it also shows a +2 and +6 oxidation state depending upon the molecule formation with electronegative atoms.

20. Radon CAS number

The CAS number of Radon molecule is 10043-92-2, which is given by the chemical abstracts service.

21. Radon Chem Spider ID

The Chem Spider ID for Radon is 55661. 

22. Radon allotropic forms

Allotropes are elements or molecules with similar chemical properties but different physical properties. Let us discuss the allotropic form of Radon.

Radon has no allotropes because it is a noble inert gas that has a filled valence shell. Due to more stability, it does not show catenation property.

23. Radon chemical classification

Radon is classified into the following categories:

  • Rn is a noble inert element
  • Rn is a gaseous element
  • Rn is a very stable element
  • Rn is a strong radioactive element

24. Radon state at room temperature

Radon exists in a gaseous state at room temperature because it has lower van der Waal’s interaction. In the crystal form, it adopts face-centered cubic structure so the atoms exist very close to each other.

25. Is Radon paramagnetic?

Paramagnetism is the tendency of magnetization in the direction of the magnetic field. Let us see whether Radon is paramagnetic or not.

Radon is not paramagnetic rather it is diamagnetic because all the electrons in the valance orbitals are in paired form.


Rn is a group 18th element so it is a noble inert gas that is radioactive in nature. Due to radioactivity, it can not be used in spectroscopy because the spectral data can not be evaluated. But for some medical purposes, it can be used.

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