Nuklida · radioaktif · alami
Uranium-234 (²³⁴U)
Uranium-234 (²³⁴U) adalah isotop radioaktif uranium dengan 92 proton dan 142 neutron (nomor massa 234). Waktu paruhnya 245,5 ribu tahun (± 0,6 ribu tahun), meluruh terutama lewat peluruhan alfa (α). Kelimpahan alaminya 0.000 054(5).
Data nuklida
- Unsur
- Uranium (U, Z = 92)
- Nomor massa (A)
- 234
- Proton (Z)
- 92
- Neutron (N)
- 142
- Massa atom
- 234.040950296 ± 0.000001212 u
- Waktu paruh
- 245,5 ribu tahun (± 0,6 ribu tahun)
- Mode peluruhan
- Peluruhan alfa (α) ( 100 %)
- Inti anak
- Torium-230 (²³⁰Th)
- Kelimpahan alami
- 0.000 054(5)
- Tahun penemuan
- 1912
- Sumber data
- IAEA Atomic Mass Data Center (NUBASE) and IUPAC CIAAW, via PubChem
Kegunaan isotop uranium
- 234U (with a half-life of 2.432×105 years) is a daughter product of 238U (with a half-life of 4.47×1010 years) and makes up only 0.0054 percent of the total uranium today. During the decay of the parent radionuclide 238U nucleus (first to 234Th (with a half-life of 24 days) by alpha decay, then to 234Pa (with a half-life of 6.7 h) by beta-minus, and finally to 234U by beta-minus), the energy released will damage the chemical and physical bonds holding the 234U product nuclei in a mineral. As a result, 234U may be leached more easily from water or rock samples than 238U and the isotope-amount ratio n(234U)/n(238U) will vary depending on the extent of water-rock interaction.
- The three natural radioactive decay chains beginning with 238U, 235U, and 232Th each have comparable half-lives that are much longer than the radioactive isotopes that follow until the production of stable isotopes of 206Pb, 207Pb, and 208Pb, respectively. When undisturbed, the activities of daughter isotopes in each decay chain are equal to their parents and one can measure the accumulation of the stable isotopes of lead to date the time that has elapsed since a mineral became a closed system (a system that does not exchange matter with its surroundings). Rocks formed hundreds of millions to billions of years ago can be dated using this technique. If a mineral is disturbed at some point during the decay and isotopes in the decay chain are preferentially removed from the system, the equilibria in a decay sequence will be disturbed. For example, one can measure the excess of 230Th (with a half-life of 7.56×104 years) relative to the 234U parent radionuclide to date carbonates (speleothems or corals) that are less than 5×105 years old.
Isotop uranium lainnya
²¹⁵U, ²¹⁶U, ²¹⁷U, ²¹⁸U, ²¹⁹U, ²²⁰U, ²²¹U, ²²²U, ²²³U, ²²⁴U, ²²⁵U, ²²⁶U, ²²⁷U, ²²⁸U, ²²⁹U, ²³⁰U, ²³¹U, ²³²U, ²³³U, ²³⁵U, ²³⁶U, ²³⁷U, ²³⁸U, ²³⁹U, ²⁴⁰U, ²⁴¹U, ²⁴²U, ²⁴³U