Krypton-84

Properties and data of the isotope ⁸⁴Kr.

Content

General data

Name of the isotope:Krypton-84; Kr-84Symbol:⁸⁴Kr or 8436KrMass number A:84 (= number of nucleons)Atomic number Z:36 (= number of protons)Neutrons N:48Isotopic mass:83.91149773(3) u (atomic weight of Krypton-84)Nuclide mass:83.8917496 u (calculated nuclear mass without electrons)Mass excess:-82.43933 MeVMass defect:0.78611939000001 u (per nucleus)Nuclear binding energy:732.26549507 MeV (per nucleus)
8.71744637 MeV (average binding energy per nucleon)Separation energy:S_N = 10.52002(1) MeV (first neutron)
S_P = 10.715(4) MeV (first proton)Half-life:stableSpin and parity:
(nuclear angular momentum)0+Charge radius:4.1884(22) femtometer fmYear of discovery:1920

Parent Nuclides

Direct parent isotopes are: ⁸⁴Rb, ⁸⁴Br.

Occurrence

Comparison of the natural Krypton isotopes including isotopic abundance (mole fraction of the isotope mixture in percent):

	Atomic Mass m_a	Quantity	Half-life	Spin
Krypton Isotopic mixture	83.798 u	100 %
Isotope ⁷⁸Kr	77.920365(5) u	0.355(3) %	stable	0+
Isotope ⁸⁰Kr	79.916378(5) u	2.286(10) %	stable	0+
Isotope ⁸²Kr	81.913483(6) u	11.593(31) %	stable	0+
Isotope ⁸³Kr	82.914127(2) u	11.500(19) %	stable	9/2+
Isotope ⁸⁴Kr	83.91149773(3) u	56.987(15) %	stable	0+
Isotope ⁸⁶Kr	85.91061063(3) u	17.279(41) %	stable	0+

Nuclear Isomers

Nuclear isomers or excited states with the activation energy in keV related to the ground state.

Nuclear Isomer	Excitation Energy	Half-life	Spin
^84m1Kr	3236.07(18) keV	1.83(4) μs	8+
^84m2Kr	5373.4(4) keV	43.7(21) ns	12+

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 48) and isobaric (same nucleon number A = 84) with Krypton-84. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 48	Isobar A = 84
26	⁷⁴Fe
27	⁷⁵Co
28	⁷⁶Ni
29	⁷⁷Cu
30	⁷⁸Zn	⁸⁴Zn
31	⁷⁹Ga	⁸⁴Ga
32	⁸⁰Ge	⁸⁴Ge
33	⁸¹As	⁸⁴As
34	⁸²Se	⁸⁴Se
35	⁸³Br	⁸⁴Br
36	⁸⁴Kr	⁸⁴Kr
37	⁸⁵Rb	⁸⁴Rb
38	⁸⁶Sr	⁸⁴Sr
39	⁸⁷Y	⁸⁴Y
40	⁸⁸Zr	⁸⁴Zr
41	⁸⁹Nb	⁸⁴Nb
42	⁹⁰Mo	⁸⁴Mo
43	⁹¹Tc
44	⁹²Ru
45	⁹³Rh
46	⁹⁴Pd
47	⁹⁵Ag
48	⁹⁶Cd
49	⁹⁷In