碳的同位素

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原子量:12.0107(8))共有15個已知同位素,其中有2個(12C與13C)是穩定的,其他都具有放射性。14C是碳唯一的天然放射性同位素,在宇宙線作用下發生14N + 1n → 14C + 1H反應而產生,半衰期為5700年。

圖表[编辑]

符號 Z(p N(n 同位素質量(u 半衰期 衰變
方式
[1]
衰變
產物
[n 1]
原子核
自旋
相對豐度
莫耳分率)
相對豐度的變化量
莫耳分率)
7C 6 1 (8.033)# (1/2+)#
8C 6 2 8.037675(25) 2.0(4) × 10−21 s
[230(50) keV]
2p 6
Be
[n 2]
0+
9C 6 3 9.0310367(23) 126.5(9) ms β+ (60%) 9
B
[n 3]
(3/2−)
β+, p (23%) 8
Be
[n 4]
β+, α (17%) 5
Li
[n 5]
10C 6 4 10.0168532(4) 19.290(12) s β+ 10
B
0+
11
C
[n 6]
6 5 11.0114336(10) 20.334(24) min β+ (99.79%) 11
B
3/2−
ε (.21%)[2][3] 11
B
12
C
6 6 12 確定的整數[n 7] 稳定 0+ 0.9893(8) 0.98853–0.99037
13
C
[n 8]
6 7 13.0033548378(10) 穩定 1/2− 0.0107(8) 0.00963–0.01147
14
C
[n 9]
6 8 14.003241989(4) 5,730 years β 14
N
0+ 痕量[n 10]天然放射性 <10−12
15C 6 9 15.0105993(9) 2.449(5) s β 15
N
1/2+
16C 6 10 16.014701(4) 0.747(8) s β, n (97.9%) 15
N
0+
β (2.1%) 16
N
17C 6 11 17.022586(19) 193(5) ms β (71.59%) 17
N
(3/2+)
β, n (28.41%) 16
N
18C 6 12 18.02676(3) 92(2) ms β (68.5%) 18
N
0+
β, n (31.5%) 17
N
19C[n 11] 6 13 19.03481(11) 46.2(23) ms β, n (47.0%) 18
N
(1/2+)
β (46.0%) 19
N
β, 2n (7%) 17
N
20C 6 14 20.04032(26) 16(3) ms
[14(+6-5) ms]
β, n (72.0%) 19
N
0+
β (28.0%) 20
N
21C 6 15 21.04934(54)# <30 ns n 20
C
(1/2+)#
22C[n 12] 6 16 22.05720(97)# 6.2(13) ms
[6.1(+14-12) ms]
β 22
N
0+

備註:畫上#號的數據代表沒有經過實驗的証明,只是理論推測而已,而用括號括起來的代表數據不確定性。


同位素列表
硼的同位素 碳的同位素 氮的同位素

註釋[编辑]

  1. ^ Bold for stable isotopes
  2. ^ Subsequently decays by double proton emission to 4He for a net reaction of 8C -> 4He + 41H
  3. ^ Immediately decays by proton emission to 8Be, which immediately decays to two 4He atoms for a net reaction of 9C -> 24He + 1H + e+
  4. ^ Immediately decays into two 4He atoms for a net reaction of 9C -> 24He + 1H + e+
  5. ^ Immediately decays by proton emission to 4He for a net reaction of 9C -> 24He + 1H + e+
  6. ^ Used for labeling molecules in PET scans
  7. ^ The unified atomic mass unit is defined as 1/12 the mass of an unbound atom of carbon-12 at ground state
  8. ^ Ratio of 12C to 13C used to measure biological productivity in ancient times and differing types of photosynthesis
  9. ^ Has an important use in radiodating (see carbon dating)
  10. ^ Primarily cosmogenic, produced by neutrons striking atoms of 14N (14N + 1n -> 14C + 1H)
  11. ^ Has 1 halo neutron
  12. ^ Has 2 halo neutrons

參考文獻[编辑]

  1. ^ Universal Nuclide Chart. nucleonica. (需要註冊 (說明)). 
  2. ^ Scobie, J.; Lewis, G. M. K-capture in carbon 11. Philosophical Magazine. 1 September 1957, 2 (21): 1089–1099 [27 March 2012]. Bibcode:1957PMag....2.1089S. doi:10.1080/14786435708242737. 
  3. ^ Campbell, J. L.; Leiper, W.; Ledingham, K. W. D.; Drever, R. W. P. The ratio of K-capture to positon emission in the decay of 11C. Nuclear Physics A: 279–287. [27 March 2012]. Bibcode:1967NuPhA..96..279C. doi:10.1016/0375-9474(67)90712-9.