Nuklida · stabil · alami

Argon-38 (³⁸Ar)

Argon-38 (³⁸Ar) adalah isotop stabil argon dengan 18 proton dan 20 neutron (nomor massa 38). Kelimpahan alaminya [0.000, 0.043].

Data nuklida

Unsur: Argon (Ar, Z = 18)
Nomor massa (A): 38
Proton (Z): 18
Neutron (N): 20
Massa atom: 37.962732102 ± 0.000000209 u
Waktu paruh: Stabil
Mode peluruhan: Tidak meluruh
Kelimpahan alami: [0.000, 0.043]
Tahun penemuan: 1934
Sumber data: IAEA Atomic Mass Data Center (NUBASE) and IUPAC CIAAW, via PubChem

Argon’s chemically inert properties and three stable isotopes make it an ideal tracer of Earth processes,,,,,,,,,,,. Measurements and models of the isotope-amount ratio n(40Ar)/n(36Ar) can provide insights about the evolution of the atmosphere and orogenic (mountain-building) history of the Earth. The comparison of results from potassium-argon and n(40Ar)/n(39Ar) isotope-amount-ratio dating methods with results from other dating methods has been used to study temperature histories of rocks through differences in apparent ages caused by excess argon or partial argon gas loss. The isotope-amount ratio n(40Ar)/n(36Ar) of dissolved argon in groundwater can provide hydrologic information, such as rates of crustal degassing and relative groundwater age. 38Ar produced by cosmic-ray bombardment of rocks and soils at Earth’s surface can provide information about surface exposure history and erosion rate.
38K (half-life of 7.6 min), which is produced by the reactions 38Ar (p, n) 38K and 40Ar (n, 3n) 38K, is a widely used blood-flow tracer. Because 38Ar is more expensive, 40Ar, which also offers many additional advantages as a target, is more commonly used to produce 38K for medical purposes,. 41Ar (half-life of 1.82 h) is used as an industrial gas-flow tracer to help track the movement of gases because its inert properties, half-life, and gamma radiation make it well suited for this purpose.