Rn Radon Index

Radon (Rn) Element Properties

Atomic Mass	222
Atomic Number	86
Name Origins	Named after the element radium.
Year Discovered	1900
Discovery Credits	Discovered by F. E. Dorn at Halle, Germany.
Remarks	Colorless, odorless gas produced by radioactive decay of radium. Little studied because of hazardous radiation which destroys any compounds that are formed. Chemically should be like xenon. Radon is present in uranium and thorium minerals as a radioactive gas which can enter the atmosphere.
References	Emsley, J., 1991; THE ELEMENTS : Sec. Ed., Clarendon Press, Oxford, 251 p.
See Also	WebElements, ChemiCool

**Naturally Occurring Isotopes**
Symbol	Isotope Mass	Isotope Nuclide Number	Isotope Number	Natural Abundance	Half-life	Half-life Units	Decay Mode	Decay Mode MeV	Decay Mode %
Rn	219.009479	219	86	0.0001%	3.96	Seconds	alpha	6.946	100.0%
Rn	220.011368	220	86	0.1000%	55.6	Seconds	alpha	6.404	100.0%
Rn	222.01757	222	86	99.9000%	3.83	Days	alpha	5.59	100.0%

Group	1	2		3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18
Period
1	1 H																		2 He
2	3 Li	4 Be												5 B	6 C	7 N	8 O	9 F	10 Ne
3	11 Na	12 Mg												13 Al	14 Si	15 P	16 S	17 Cl	18 Ar
4	19 K	20 Ca		21 Sc	22 Ti	23 V	24 Cr	25 Mn	26 Fe	27 Co	28 Ni	29 Cu	30 Zn	31 Ga	32 Ge	33 As	34 Se	35 Br	36 Kr
5	37 Rb	38 Sr		39 Y	40 Zr	41 Nb	42 Mo	43 Tc	44 Ru	45 Rh	46 Pd	47 Ag	48 Cd	49 In	50 Sn	51 Sb	52 Te	53 I	54 Xe
6	55 Cs	56 Ba	*	71 Lu	72 Hf	73 Ta	74 W	75 Re	76 Os	77 Ir	78 Pt	79 Au	80 Hg	81 Tl	82 Pb	83 Bi	84 Po	85 At	86 Rn
7	87 Fr	88 Ra	**	103 Lr	104 Rf	105 Db	106 Sg	107 Bh	108 Hs	109 Mt	110 Ds
-
*Lanthanides			*	57 La	58 Ce	59 Pr	60 Nd	61 Pm	62 Sm	63 Eu	64 Gd	65 Tb	66 Dy	67 Ho	68 Er	69 Tm	70 Yb
**Actinides			**	89 Ac	90 Th	91 Pa	92 U	93 Np	94 Pu	95 Am	96 Cm	97 Bk	98 Cf	99 Es	100 Fm	101 Md	102 No