Isotop nitrogen
Nitrogen alam (7N) terdiri dari dua isotop stabil, nitrogen-14, yang membentuk sebagian besar nitrogen alami, dan nitrogen-15. Empat belas isotop radioaktif (radioisotop) juga telah ditemukan sejauh ini, dengan massa atom berkisar antara 10 sampai 25, dan satu isomer nuklir, 11mN. Semua radioisotop ini berumur pendek, dengan yang berumur terpanjang adalah nitrogen-13 dengan waktu paruh 9.965 menit. Semua yang lainnya memiliki waktu paruh di bawah 7,15 detik, dengan sebagian besar berada di bawah lima per delapan detik. Sebagian besar isotop dengan nomor massa atom di bawah 14 meluruh menjadi isotop karbon, sementara sebagian besar isotop dengan massa di atas 15 meluruh menjadi isotop oksigen. Isotop paling pendek yang diketahui adalah nitrogen-10, dengan waktu paruh sekitar 2,3 mikrodetik.
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| Berat atom standar Ar°(N) |
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Daftar isotop
| nuclide symbol |
Z(p) | N(n) | isotopic mass (u) |
half-life | decay mode(s)[2] | daughter isotope(s)[n 1] |
nuclear spin |
representative isotopic composition (mole fraction) |
range of natural variation (mole fraction) |
|---|---|---|---|---|---|---|---|---|---|
| excitation energy | |||||||||
| 10N | 7 | 3 | 10.04165(43) | 200(140)×10−24 s [2.3(16) MeV] |
p | C | (2−) | ||
| 11N | 7 | 4 | 11.02609(5) | 590(210)×10−24 s [1.58(+75−52) MeV] |
p | C | 1/2+ | ||
| 11mN | 740(60) keV | 6.90(80)×10−22 s | 1/2− | ||||||
| 12N | 7 | 5 | 12.0186132(11) | 11.000(16) ms | β+ (96.5%) | C | 1+ | ||
| β+, α (3.5%) | unknown element Beryllium.[n 2] | ||||||||
| 13N[n 3] | 7 | 6 | 13.00573861(29) | 9.965(4) min | β+ | C | 1/2− | ||
| 14N | 7 | 7 | 14.0030740048(6) | Stable | 1+ | 0.99636(20) | 0.99579–0.99654 | ||
| 15N | 7 | 8 | 15.0001088982(7) | Stable | 1/2− | 0.00364(20) | 0.00346–0.00421 | ||
| 16N | 7 | 9 | 16.0061017(28) | 7.13(2) s | β− (99.99%) | O | 2− | ||
| β−, α (.001%) | C | ||||||||
| 17N | 7 | 10 | 17.008450(16) | 4.173(4) s | β−, n (95.0%) | O | 1/2− | ||
| β− (4.99%) | O | ||||||||
| β−, α (.0025%) | C | ||||||||
| 18N | 7 | 11 | 18.014079(20) | 622(9) ms | β− (76.9%) | O | 1− | ||
| β−, α (12.2%) | C | ||||||||
| β−, n (10.9%) | O | ||||||||
| 19N | 7 | 12 | 19.017029(18) | 271(8) ms | β−, n (54.6%) | O | (1/2−) | ||
| β− (45.4%) | 19O | ||||||||
| 20N | 7 | 13 | 20.02337(6) | 130(7) ms | β−, n (56.99%) | 19O | |||
| β− (43.00%) | 20O | ||||||||
| 21N | 7 | 14 | 21.02711(10) | 87(6) ms | β−, n (80.0%) | 20O | 1/2−# | ||
| β− (20.0%) | 21O | ||||||||
| 22N | 7 | 15 | 22.03439(21) | 13.9(14) ms | β− (65.0%) | 22O | |||
| β−, n (35.0%) | 21O | ||||||||
| 23N | 7 | 16 | 23.04122(32)# | 14.5(24) ms [14.1(+12−15) ms] |
β− | 23O | 1/2−# | ||
| 24N | 7 | 17 | 24.05104(43)# | <52 ns | n | 23N | |||
| 25N | 7 | 18 | 25.06066(54)# | <260 ns | 1/2−# | ||||
- ^ Bold for stable isotopes.
- ^ Immediately decays into two alpha particles for a net reaction of 12N → 3 4He + e+.
- ^ Used in positron emission tomography.
Catatan
- The precision of the isotope abundances and atomic mass is limited through variations. The given ranges should be applicable to any normal terrestrial material.
- Values marked # are not purely derived from experimental data, but at least partly from systematic trends. Spins with weak assignment arguments are enclosed in parentheses.
- Uncertainties are given in concise form in parentheses after the corresponding last digits. Uncertainty values denote one standard deviation, except isotopic composition and standard atomic mass from IUPAC, which use expanded uncertainties.
- Nuclide masses are given by IUPAP Commission on Symbols, Units, Nomenclature, Atomic Masses and Fundamental Constants (SUNAMCO).
- Isotope abundances are given by IUPAC Commission on Isotopic Abundances and Atomic Weights (CIAAW).
Referensi
- ^ Meija, J.; et al. (2016). "Atomic weights of the elements 2013 (IUPAC Technical Report)". Pure Appl. Chem. 88 (3): 265–91. doi:10.1515/pac-2015-0305.
- ^ "Universal Nuclide Chart". nucleonica. (Perlu mendaftar (help)).