Hubbry Logo
Isotopes of potassiumIsotopes of potassiumMain
Open search
Isotopes of potassium
Community hub
Isotopes of potassium
logo
7 pages, 0 posts
0 subscribers
Be the first to start a discussion here.
Be the first to start a discussion here.
Isotopes of potassium
Isotopes of potassium
Isotopes of potassium
View on Wikipedia
from Wikipedia

Isotopes of potassium (19K)
Main isotopes Decay
Isotope abun­dance half-life (t1/2) mode pro­duct
39K 93.3% stable
40K 0.0117% 1.248×109 y β− 40Ca
ε 40Ar
β+ 40Ar
41K 6.73% stable
Standard atomic weight Ar°(K)

Potassium (
19K) has 25 known isotopes from 34
K to 57
K as well as 31
K, as well as an unconfirmed report of 59
K.[3] Three of those isotopes occur naturally: the two stable forms 39
K (93.26%) and 41
K (6.72%), and the long-lived radioisotope 40
K (0.012%).

Naturally occurring radioactive 40
K decays with a half-life of 1.248×109 years. 89% of those decays are to stable 40
Ca by beta decay, whilst 11% are to 40
Ar by either electron capture or positron emission. This latter decay branch has produced an isotopic abundance of argon on Earth which differs greatly from that seen in gas giants and stellar spectra. 40
K has the longest known half-life for any positron-emitting nuclide.[4] The long half-life of this primordial radioisotope is caused by a highly spin-forbidden transition: 40
K has a nuclear spin of 4, while both of its decay daughters are even–even isotopes with spins of 0.

40
K occurs in natural potassium in sufficient quantity that large bags of potassium chloride commercial salt substitutes can be used as a radioactive source for classroom demonstrations.[citation needed] 40
K is the largest source of natural radioactivity in healthy animals and humans, greater even than 14
C. In a human body of 70 kg mass, about 4300 nuclei of 40
K decay per second.[5]

The decay of 40
K to 40
Ar is used in potassium-argon dating of rocks. Minerals are dated by measurement of the concentration of potassium and the amount of radiogenic 40
Ar that has accumulated. 40
K has also been extensively used as a radioactive tracer in studies of weathering.[citation needed]

All other potassium isotopes have half-lives under a day, most under a minute. The unbound 31
K was discovered in 2019 and emits three protons; its half-life was measured to be shorter than 10 picoseconds.[6][7]

Stable potassium isotopes have been used for several nutrient cycling studies since potassium is a macronutrient required for life.[8]

List of isotopes

[edit]


Nuclide
[n 1] 		Z N Isotopic mass (Da)[9]
[n 2][n 3] 		Half-life[10]
[n 4] 		Decay
mode[10]
 Daughter
isotope
[n 5] 		Spin and
parity[10]
[n 6][n 4] 		Natural abundance (mole fraction)
Excitation energy[n 4] Normal proportion[10] Range of variation
31
K[6][7] 		19 12 31.03678(32)# <10 ps 3p 28S 3/2+#
34K[11] 19 15 33.998404(18) p 33Ar
35K 19 16 34.98800541(55) 175.2(19) ms β+ (99.63%) 35Ar 3/2+
β+, p (0.37%) 34Cl
36K 19 17 35.98130189(35) 341(3) ms β+ (99.95%) 36Ar 2+
β+, p (0.048%) 35Cl
β+, α (0.0034%) 32S
37K 19 18 36.97337589(10) 1.23651(94) s β+ 37Ar 3/2+
38K 19 19 37.96908111(21) 7.651(19) min β+ 38Ar 3+
38m1K 130.15(4) keV 924.35(12) ms β+ (99.97%) 38Ar 0+
IT (0.0330%) 38K
38m2K 3458.10(17) keV 21.95(11) μs IT 38K (7)+
39K 19 20 38.9637064848(49) Stable 3/2+ 0.932581(44)
40K[n 7][n 8] 19 21 39.963998165(60) 1.248(3)×109 y β− (89.28%) 40Ca 4− 1.17(1)×10−4
EC (10.72%) 40Ar
β+ (0.001%)[12]
40mK 1643.638(11) keV 336(12) ns IT 40K 0+
41K 19 22 40.9618252561(40) Stable 3/2+ 0.067302(44)
42K 19 23 41.96240231(11) 12.355(7) h β− 42Ca 2−
43K 19 24 42.96073470(44) 22.3(1) h β− 43Ca 3/2+
43mK 738.30(6) keV 200(5) ns IT 43K 7/2−
44K 19 25 43.96158698(45) 22.13(19) min β− 44Ca 2−
45K 19 26 44.96069149(56) 17.8(6) min β− 45Ca 3/2+
46K 19 27 45.96198158(78) 96.30(8) s β− 46Ca 2−
47K 19 28 46.9616616(15) 17.38(3) s β− 47Ca 1/2+
48K 19 29 47.96534118(83) 6.83(14) s β− (98.86%) 48Ca 1−
β−, n (1.14%) 47Ca
49K 19 30 48.96821075(86) 1.26(5) s β−, n (86%) 48Ca 1/2+
β− (14%) 49Ca
50K 19 31 49.9723800(83) 472(4) ms β− (71.4%) 50Ca 0−
β−, n (28.6%) 49Ca
β−, 2n? 48Ca
50mK 172.0(4) keV 125(40) ns IT 50K (2−)
51K 19 32 50.975828(14) 365(5) ms β−, n (65%) 50Ca 3/2+
β− (35%) 51Ca
β−, 2n? 49Ca
52K 19 33 51.981602(36) 110(4) ms β−, n (72.2%) 51Ca 2−#
β− (25.5%) 52Ca
β−, 2n (2.3%) 50Ca
53K 19 34 52.98680(12) 30(5) ms β−, n (64%) 52Ca 3/2+
β− (26%) 53Ca
β−, 2n (10%) 51Ca
54K 19 35 53.99447(43)# 10(5) ms β− 54Ca 2−#
β−, n? 53Ca
β−, 2n? 52Ca
55K 19 36 55.00051(54)# 10# ms
[>620 ns] 		β−? 55Ca 3/2+#
β−, n? 54Ca
β−, 2n? 53Ca
56K 19 37 56.00857(64)# 5# ms
[>620 ns] 		β−? 56Ca 2−#
β−, n? 55Ca
β−, 2n? 54Ca
57K 19 38 57.01517(64)# 2# ms
[>400 ns] 		β−? 57Ca 3/2+#
β−, n? 56Ca
β−, 2n? 55Ca
59K[3][n 9] 19 40 59.03086(86)# 1# ms
[>400 ns] 		β−? 59Ca 3/2+#
β−, n? 58Ca
β−, 2n? 57Ca
This table header & footer:
  1. ^ mK – Excited nuclear isomer.
  2. ^ ( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
  3. ^ # – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).
  4. ^ a b c # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
  5. ^ Bold symbol as daughter – Daughter product is stable.
  6. ^ ( ) spin value – Indicates spin with weak assignment arguments.
  7. ^ Used in potassium-argon dating
  8. ^ Primordial radionuclide
  9. ^ Discovery of this isotope is unconfirmed.

See also

[edit]

Daughter products other than potassium

References

[edit]
Revisions and contributorsEdit on WikipediaRead on Wikipedia

Isotopes of potassium

View on Grokipedia
from Grokipedia
Potassium (Z = 19) has three naturally occurring : the stable isotopes 39K and 41K, and the long-lived radioactive isotope 40K. The isotope 39K accounts for 93.2581(44)% of natural potassium, 41K for 6.7302(44)%, and 40K for 0.0117(1)%. The latter decays primarily to 40Ca (89.28%) via β⁻ emission and to 40Ar (10.72%) via , with a of 1.248(3) × 109 years. Twenty-six isotopes of are known in total, spanning mass numbers from 31 to 56, with all except 39, 41, and 40 being unstable and exhibiting half-lives ranging from microseconds to days. The primordial 40 plays a key role in , particularly in the potassium-argon (K-Ar) and argon-argon (Ar-Ar) dating methods for igneous and metamorphic rocks, as its decay accumulates 40Ar in minerals. Additionally, the 39 and 41 serve as tracers in environmental and biological studies to track cycling in ecosystems and uptake in plants and animals, given 's essential role as a macronutrient. Recent research has also explored ratios (e.g., δ41) for insights into planetary formation, magmatic processes, and early Solar heterogeneity.

Introduction and history

Overview of potassium isotopes

Potassium, with 19, has 25 known isotopes from 31^{31} and 34^{34} to 57^{57}, along with an unconfirmed report of 59^{59}. These isotopes differ by their numbers, which vary from 12 (for 31^{31}) to 38 (for 57^{57}). The nuclear properties of these isotopes, including their masses and decay characteristics, are documented in comprehensive evaluations such as NUBASE2020. Only three isotopes occur naturally: 39^{39}K, 40^{40}K, and 41^{41}K, which constitute essentially all terrestrial . Their isotopic abundances are 39^{39}K at 93.2581%, 40^{40}K at 0.0117%, and 41^{41}K at 6.7302%. Due to its odd , lacks fully isotopes in the absolute sense, as the unpaired proton contributes to potential decay pathways influenced by binding energies; however, 39^{39}K and 41^{41}K are effectively , while 40^{40}K is a primordial radioactive with a of 1.248(3) ×109\times 10^9 years. The stability of isotopes aligns with the , where binding energies per peak near the valley of stability for this , favoring even-neutron configurations for the long-lived . The of is the abundance-weighted average of the masses of its natural : Ar(\ceK)=∑ifi⋅AiA_\text{r}(\ce{K}) = \sum_i f_i \cdot A_i where fif_i is the fractional abundance of isotope ii and AiA_i is its (or more precisely, ). This yields Ar(\ceK)=39.0983(1)A_\text{r}(\ce{K}) = 39.0983(1).

Historical development

The element was first isolated in 1807 by British chemist through of (caustic potash), marking the inaugural use of to extract a metal from its compound. In 1921, identified the stable isotopes ^{39}K and ^{41}K using his newly developed mass spectrograph at the , resolving discrepancies in potassium's atomic weight and confirming the existence of isotopic variations among elements. Radioactivity in natural potassium samples had been observed as early as 1908 by N. R. Campbell, though its isotopic origin remained unidentified until later. The radioactive nature of ^{40}K was established in 1935, when Alfred O. C. Nier provided mass spectrometric evidence for its existence as a minor of potassium, and subsequent studies by H. Walke attributed the long-observed activity in natural potassium samples specifically to ^{40}K. Following , significant progress in isotope production occurred in the late and , with nuclear reactors and particle accelerators enabling the synthesis and separation of unstable potassium isotopes such as ^{42}K and ^{43}K for research purposes, building on wartime technologies developed for enrichment. Measurements of the ^{40}K half-life were refined during the and through improved beta-counting and mass spectrometric techniques, yielding values converging around 1.25 billion years; notable contributions included T. P. Kohman's 1956 compilation estimating 1.35 ± 0.05 billion years and J. C. Emery's determination of 1.27 ± 0.05 billion years, which enhanced the accuracy of geochronological applications.

Natural composition

Abundance in nature

Potassium occurs naturally as a mixture of three isotopes: ^{39}K, which constitutes 93.2581% of the total, ^{40}K at 0.0117%, and ^{41}K at 6.7302%. These proportions reflect the primordial isotopic composition established during Earth's formation, with minor adjustments over geological timescales due to the radioactive decay of ^{40}K, which has a half-life of approximately 1.25 billion years and thus results in only subtle depletion of this isotope relative to the stable ones. In the , potassium is the seventh most abundant element, comprising about 2.6% by weight, primarily in minerals such as feldspars and micas. In , its concentration averages around 380 mg/L (or roughly 10 mmol/kg), while in soils, total potassium content typically ranges from 1.5% to 2.5% by weight, depending on and processes. Across these reservoirs, the isotopic ratios of potassium generally adhere to the primordial values, as produces negligible quantities of lighter isotopes in terrestrial environments compared to extraterrestrial materials like meteorites. Slight variations in the ^{41}K/^{39}K ratio, on the order of 0.1% to 1%, arise from isotopic processes, including biological uptake by and microorganisms, which preferentially incorporate lighter isotopes, and in surface waters or high-temperature geological settings, where heavier isotopes are enriched in the vapor phase. These effects are minor and do not significantly alter the overall natural abundance. The standard atomic weight of potassium, 39.0983(1), is calculated directly from these isotopic abundances and masses, providing a weighted average used in chemical and physical calculations.

Stable and primordial radioactive isotopes

Potassium possesses two stable isotopes, ³⁹K and ⁴¹K, alongside the primordial radioactive isotope ⁴⁰K, which together constitute the natural isotopic composition of the element. These isotopes exhibit distinct nuclear properties that influence their roles in geochemical and geochronological processes. The isotope ³⁹K is the most abundant stable form of potassium, with an atomic mass of 38.9637064864(49) u and a ground-state nuclear spin and parity of 3/2⁺. As a , ³⁹K does not undergo and dominates the weighted average of potassium. The less abundant stable isotope ⁴¹K has an of 40.9618252579(41) u and a ground-state spin and parity of 3/2⁺, rendering it non-radioactive. It serves as a key tracer in studies, particularly for investigating processes in geological and biological systems due to its distinct mass difference from ³⁹K. In contrast, ⁴⁰K is a long-lived radioactive isotope with an atomic mass of 39.963998166(60) u and a ground-state spin and parity of 4⁻. It has a of 1.2522(27) × 10⁹ years and decays via two primary branches: β⁻ emission to ⁴⁰Ca with a branching ratio of 89.56(7)% and an endpoint energy (E_max) of 1.312 MeV, and (primarily to an excited state of ⁴⁰Ar) with a total branching ratio of approximately 10.44%, corresponding to a Q-value of 1.505 MeV (β⁺ branching is negligible at 0.001%). The decay modes are represented by the following equations: 40K→40Ca+e−+νˉe^{40}\mathrm{K} \to ^{40}\mathrm{Ca} + e^- + \bar{\nu}_e (for β⁻ decay, 89.56(7)% branch) 40K+e−→40Ar+νe^{40}\mathrm{K} + e^- \to ^{40}\mathrm{Ar} + \nu_e (for electron capture, ~10.44% branch). ⁴⁰K is primordial in origin, produced primarily through nucleosynthesis in type II supernovae explosions that enriched the presolar molecular cloud from which the Solar System formed approximately 4.6 billion years ago. Its ongoing decay contributes significantly to Earth's internal heat budget, generating approximately 4 TW of radiogenic power through the release of decay energy in the crust and mantle.

Synthetic isotopes

Methods of synthesis

Artificial potassium isotopes are synthesized primarily through charged-particle induced nuclear in accelerators, in reactors, and high-energy processes at specialized facilities. These methods allow for the production of neutron-deficient and neutron-rich isotopes beyond those occurring naturally, enabling research and applications in and . Proton and deuteron bombardment of target materials such as calcium and in cyclotrons is a common technique for generating neutron-deficient potassium isotopes. For instance, the reaction ^{35}Cl(α,n)^{38}K on NaCl , using energies around 14.7 MeV, yields significant amounts of ^{38}K suitable for studies, with production rates up to 20-30 mCi per . Similarly, the ^{38}Ar(p,n)^{38}K reaction on enriched ^{38}Ar at lower energies (16-12 MeV) provides high-purity output, achieving saturation yields of approximately 21 mCi/μA·h in compact cyclotrons. Deuteron reactions on calcium , such as ^{40}Ca(d,α)^{38}K, have also been employed historically for short-lived isotopes. These cyclotron-based methods rely on water-cooled gas or , followed by chemical to isolate the product. Neutron-rich potassium isotopes are produced via radiative capture reactions in nuclear reactors. The ^{41}K(n,\gamma)^{42}K reaction on enriched targets, such as , is irradiated under fluxes (typically 10^{13}-10^{15} n/cm²/s) for periods ranging from hours to weeks, depending on desired activity. This method, standard since the mid-20th century, generates ^{42}K as a beta-emitter for tracer studies, with post-irradiation purification involving dissolution and ion-exchange chromatography to remove impurities like ^{82}Br. Reactor production favors neutron excess due to the abundance of s, contrasting with accelerator methods for proton-rich nuclides. Lighter, more exotic potassium isotopes (e.g., ^{34}K to ^{38}K) are synthesized through and fragmentation at high-energy proton accelerators. Facilities like ISOLDE at use 1.4 GeV proton beams incident on thick targets such as uranium carbide (UC_x), inducing to fragment heavy nuclei into a broad distribution of light isotopes, including . The resulting ions are thermalized, ionized, and separated on-line via for beam delivery. This technique, evolved from earlier fragmentation experiments, excels in producing rare, short-lived species for nuclear structure studies. Enrichment of stable potassium isotopes (^{39}K and ^{41}K) for use as targets or tracers employs separation techniques including electromagnetic isotope separation (), chemical exchange, and methods. , developed in the , ionize potassium salts and separate isotopes in magnetic fields based on mass-to-charge ratios, achieving high enrichment for research quantities. Chemical isotope exchange between aqueous solutions of potassium halides (e.g., and ) exploits slight differences, while modern magneto-optical approaches use to selectively excite and separate atomic states of specific isotopes, offering scalability for preparative amounts. Production has shifted from early reactor and setups to contemporary high-intensity accelerators like ISOLDE, improving yield and purity for exotic isotopes.

Key synthetic isotopes and their half-lives

Synthetic isotopes of potassium are artificially produced radioactive nuclides that do not occur naturally in significant quantities, spanning a range from proton-rich lighter isotopes to neutron-rich heavier ones. Among the key mid-mass synthetic isotopes, ^{42}K has a of 12.36(1) hours and undergoes β⁻ decay to ^{42}Ca with a maximum energy of 3.525(2) MeV. This isotope is commonly produced via the reaction ^{41}K(n,γ)^{42}K in nuclear reactors. Similarly, ^{43}K possesses a of 22.3(1) hours and decays primarily by β⁻ emission to ^{43}Ca with E_max = 1.833(5) MeV; it is synthesized through the (n,p) reaction on ^{43}Ca targets. Lighter synthetic isotopes, such as ^{35}K, exhibit very short half-lives and are valuable for probing nuclear structure. ^{35}K has a half-life of 178(8) ms and decays via β⁺ emission and proton decay to ^{34}Cl, with a total Q-value of 11.874(9) MeV. These proton-rich isotopes are typically generated in high-energy projectile fragmentation reactions or spallation processes at particle accelerators. On the neutron-rich side, heavier isotopes like ^{52}K have a half-life of 110(6) ms and decay predominantly by β⁻ emission to ^{52}Ca (23.7%), accompanied by neutron emission branches (β⁻,n to ^{51}Ca at 74% and β⁻,2n to ^{50}Ca at 2.3%), with Q = 17.13(3) MeV. Such isotopes are observed and produced via projectile fragmentation of heavy targets, such as uranium, with high-energy protons at facilities like ISOLDE. Overall, half-lives of synthetic potassium isotopes decrease from hours in the mid-mass region (around A ≈ –45) to milliseconds or shorter at the extremes (A < 38 or A > 50), reflecting increasing instability far from the line of β-stability. Decay modes are primarily β⁻ for neutron-rich isotopes, facilitating proton-to-neutron conversion, while proton-rich isotopes favor β⁺/ and, in lighter cases, . The following table summarizes selected key synthetic isotopes, highlighting their , half-life, primary decay mode, and a representative production reaction where characteristically documented:
Mass NumberHalf-LifeDecay ModeProduction Reaction Example
^{35}K178(8) msβ⁺, p (to ^{34}Cl)Projectile fragmentation
^{36}K341(3) msβ⁺/EC, p, α (to ^{36}Ar)High-energy spallation
^{37}K1.225(7) sβ⁺ (to ^{37}Ar)Projectile fragmentation
^{38}K7.651(19) minβ⁺/EC (to ^{38}Ar)^{38}Ar(p,n) or photonuclear
^{42}K12.36(1) hβ⁻ (to ^{42}Ca)^{41}K(n,γ)
^{43}K22.3(1) hβ⁻ (to ^{43}Ca)^{43}Ca(n,p)
^{44}K22.13(19) minβ⁻ (to ^{44}Ca)^{44}Ca(n,p) or ^{45}Sc(p,n)
^{45}K17.81(61) minβ⁻ (to ^{45}Ca)^{46}Sc(p,2n) or neutron rxn.
^{46}K105(10) sβ⁻ (to ^{46}Ca)Neutron-induced reactions
^{47}K17.50(24) sβ⁻ (to ^{47}Ca)Neutron-induced reactions
^{48}K6.8(2) sβ⁻, β⁻ n (to ^{48,47}Ca)Projectile fragmentation
^{49}K1.26(5) sβ⁻, β⁻ n (to ^{49,48}Ca)Projectile fragmentation
^{50}K472(4) msβ⁻, β⁻ n (to ^{50,49}Ca)Projectile fragmentation
^{52}K110(6) msβ⁻, β⁻ n, β⁻ 2n (to ^{52,51,50}Ca)Proton-induced fragmentation of U

Scientific and practical applications

Geochronology and Earth sciences

Potassium-argon (K-Ar) dating is a radiometric method that determines the age of geological materials by measuring the accumulation of the stable isotope argon-40 (⁴⁰Ar) produced from the decay of radioactive (⁴⁰K) in minerals and rocks, particularly those from volcanic origins such as potassium-bearing feldspars and micas. This technique assumes that at the time of rock formation, no initial ⁴⁰Ar was present and that the argon produced remains trapped within the lattice, allowing the ratio of ⁴⁰Ar to ⁴⁰K to reflect the time elapsed since solidification. The method is effective for dating events ranging from approximately 100,000 years to several billion years old, making it suitable for studying ancient geological processes. The age calculation in K-Ar dating follows the law, given by the equation: t=1λln⁡(1+40Ar40K)t = \frac{1}{\lambda} \ln\left(1 + \frac{{^{40}\mathrm{Ar}}}{{^{40}\mathrm{K}}}\right) where tt is the age in years, 40Ar{^{40}\mathrm{Ar}} and 40K{^{40}\mathrm{K}} are the measured amounts of the isotopes, and λ\lambda is the total decay constant for ⁴⁰K, valued at 5.543×10−105.543 \times 10^{-10} yr⁻¹, which accounts for both to ⁴⁰Ar (about 11%) and to ⁴⁰Ca (about 89%). Measurements involve precise to quantify and content after chemical separation. An advanced variant, the ⁴⁰Ar/³⁹Ar dating method, enhances precision by irradiating the sample with neutrons to convert a portion of stable ³⁹K to ³⁹Ar, creating a proxy for total content that can be measured alongside ⁴⁰Ar in a single analysis. This approach allows step-wise heating to release incrementally, revealing potential disturbances like loss or excess, and enables dating of smaller samples or those with low concentrations. It uses the same decay constant as K-Ar but calculates ages relative to a monitor standard of known age, improving accuracy for complex geological histories. In Earth sciences, K-Ar and ⁴⁰Ar/³⁹Ar methods have been applied to date meteorites, providing insights into the early solar system's timeline, such as the ages of chondrites exceeding 4.5 billion years. Lunar samples from Apollo missions were dated using these techniques to establish the Moon's volcanic history, revealing basaltic flows from 3.1 to 4.2 billion years ago. They also constrain events by dating volcanic rocks associated with zones and mid-ocean ridges, such as the timing of phases. Additionally, the decay of ⁴⁰K contributes to through radiogenic heating, generating approximately 4 terawatts of power and accounting for about 5-10% of the planet's total surface of roughly 44 terawatts. This heat production sustains , driving geological activity like and plate movements over billions of years.

Tracer applications in biology and industry

Stable isotopes of potassium, particularly ⁴¹K and ³⁹K, serve as tracers in to investigate nutrient uptake and cycling in . In studies, enrichment with ⁴¹K allows researchers to quantify potassium absorption, translocation, and recovery efficiency in crops like corn, revealing patterns during growth that inform soil-plant interactions. Similarly, in animal and aquatic organisms such as and , ⁴¹K/³⁹K ratios track transcellular potassium transport and metabolic processes, providing insights into without radiological risks. These non-radioactive tracers enable precise, long-term monitoring of potassium dynamics in ecological and agricultural contexts. The naturally occurring radioactive isotope ⁴⁰K, along with short-lived synthetic isotopes like ⁴²K, is utilized to assess total body potassium non-invasively through whole-body counting techniques. In adults, the typical ⁴⁰K body burden averages approximately 4,400 Bq, corresponding to about 140 g of total , which serves as a for nutritional status, muscle mass, and metabolic health. This method detects gamma emissions from ⁴⁰K to estimate accurately, aiding clinical evaluations in and . In , ⁴²K, a beta-emitting with a of approximately 12 hours, has been used in to study coronary blood flow and distribution. Its decay properties allow visualization of exchange in cardiovascular and physiological processes, enabling safe dosing for dynamic in clinical settings. Industrial applications leverage radioactive potassium isotopes, such as ⁴²K and ⁴³K, as tracers to evaluate efficiency and material integrity. In , ⁴²K tracers track uptake and transport rates in plant roots, as demonstrated in rice studies where it highlighted differences in ion mobility compared to cesium, optimizing nutrient delivery and reducing waste. Radioactive potassium isotopes have also been explored for monitoring processes in industrial fluids using broader radiotracer techniques for and wear analysis. Safety considerations for these tracers emphasize their low radiation doses, comparable to natural background levels. The annual internal dose from ⁴⁰K in the is equivalent to consuming about 2,400 , with each banana delivering roughly 0.1 μSv from its content. This equivalence underscores the minimal risk associated with tracer applications, as doses from short-lived isotopes like ⁴²K are designed to stay well below regulatory limits for biological and industrial use.

References

  1. https://physics.nist.gov/cgi-bin/Compositions/stand_alone.pl?ele=K
  2. https://atom.kaeri.re.kr/cgi-bin/nuclide?nuc=K40
  3. https://pse-info.de/en/isotopes/K
  4. https://wwwrcamnl.wr.usgs.gov/isoig/period/k_iig.html
  5. https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2022.1016242/full
  6. https://www.nature.com/articles/s41467-022-35362-7
  7. https://iopscience.iop.org/article/10.1088/1674-1137/abddae
  8. https://ciaaw.org/potassium.htm
  9. https://www.chem.ualberta.ca/~massspec/atomic_mass_abund.pdf
  10. https://pubchem.ncbi.nlm.nih.gov/element/Potassium
  11. https://doi.org/10.1016/j.chemer.2021.125786
  12. https://answersresearchjournal.org/radioisotope-decay-potassium-40/
  13. https://link.aps.org/doi/10.1103/PhysRev.52.663
  14. https://www-pub.iaea.org/MTCD/Publications/PDF/trs465_web.pdf
  15. http://www.lnhb.fr/pdf/Conferences/LNHB-ICRM2025-P2-35.pdf
  16. http://hyperphysics.phy-astr.gsu.edu/hbase/pertab/k.html
  17. https://www.lenntech.com/composition-seawater.htm
  18. https://pubs.usgs.gov/sir/2017/5118/sir20175118_element.php?el=19
  19. https://pmc.ncbi.nlm.nih.gov/articles/PMC8740523/
  20. https://www.sciencedirect.com/science/article/abs/pii/S0009254119302177
  21. https://www.nndc.bnl.gov/nndc/stone_moments/nuclear-moments.pdf
  22. https://www.sciencedirect.com/science/article/abs/pii/S0009254121000887
  23. https://www.physoc.org/magazine-articles/40k-from-ancient-supernovae-to-bananas-and-beyond/
  24. https://www.interactions.org/press-release/what-keeps-earth-cooking
  25. https://www-pub.iaea.org/MTCD/Publications/PDF/te_1340_web.pdf
  26. https://jnm.snmjournals.org/content/jnumed/21/9/867.full.pdf
  27. https://www.sciencedirect.com/science/article/pii/088328899290132X
  28. https://www.sciencedirect.com/topics/earth-and-planetary-sciences/deuteron
  29. https://cds.cern.ch/record/526080/files/open-2001-075.pdf
  30. https://www.annualreviews.org/doi/pdf/10.1146/annurev.ns.01.120152.001403
  31. https://inis.iaea.org/records/xk88d-vkv97
  32. https://link.springer.com/article/10.1007/s11467-021-1129-y
  33. https://www.nndc.bnl.gov/nudat3/
  34. https://www.nature.com/articles/135580a0
  35. https://pubmed.ncbi.nlm.nih.gov/5055367/
  36. https://cds.cern.ch/record/134702/files/378.pdf
  37. https://geoinfo.nmt.edu/labs/argon/methods/home.html
  38. https://www2.tulane.edu/~sanelson/eens212/radiometric_dating.htm
  39. https://pubs.geoscienceworld.org/msa/rimg/article/47/1/785/235420/K-Ar-and-Ar-Ar-Dating
  40. https://www.ucl.ac.uk/~ucfbpve/geotopes/indexch6.html
  41. https://pubs.geoscienceworld.org/gsa/gsabulletin/article/133/3-4/461/587798/Interpreting-and-reporting-40Ar-39Ar
  42. https://pubs.acs.org/doi/10.1021/acsearthspacechem.2c00105
  43. https://pmc.ncbi.nlm.nih.gov/articles/PMC9644202/
  44. https://pmc.ncbi.nlm.nih.gov/articles/PMC4844139/
  45. https://www.measurement-toolkit.org/anthropometry/objective-methods/whole-body-counting-of-total-body-potassium
  46. https://world-nuclear.org/information-library/non-power-nuclear-applications/radioisotopes-research/radioisotopes-in-medicine
  47. https://www.researchgate.net/publication/287106544_Tracer_experiment_using_42K_and_137Cs_revealed_the_different_transport_rates_of_potassium_and_caesium_within_rice_roots
  48. https://www.epa.gov/radtown/natural-radioactivity-food
Add your contribution
Related Hubs
User Avatar
No comments yet.