鈣的同位素

**主要的鈣同位素**
標準原子質量（英语：Standard atomic weight） (Ar, 標準)	40.078(4);
←K（19）	Sc（21）→
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鈣（原子量：40.078(4)）共有24個同位素，其中有3個是穩定的。

圖表

符號	Z（ p ）	N（ n ）	同位素質量（u）	半衰期^{[n 1]}	衰變方式^[2]^{[n 2]}	衰變產物^{[n 3]}	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）
34 Ca	20	14	34.01412(32)#	<35 ns	p	³³K	0+
35 Ca	20	15	35.00494(21)#	25.7(2) ms	β⁺ (>99.9%)	³⁵K	1/2+#
35 Ca	20	15	35.00494(21)#	25.7(2) ms	β⁺, p (<.1%)	³⁴Ar	1/2+#
36 Ca	20	16	35.99309(4)	102(2) ms	β⁺, p (56.8%)	³⁵Ar	0+
36 Ca	20	16	35.99309(4)	102(2) ms	β⁺ (43.2%)	³⁶K	0+
37 Ca	20	17	36.985870(24)	181.1(10) ms	β⁺, p (74.5%)	³⁶Ar	(3/2+)
37 Ca	20	17	36.985870(24)	181.1(10) ms	β⁺ (25.5%)	³⁷K	(3/2+)
38 Ca	20	18	37.976318(5)	440(8) ms	β⁺	³⁸K	0+
39 Ca	20	19	38.9707197(20)	859.6(14) ms	β⁺	³⁹K	3/2+
40 Ca ^{[n 4]}	20	20	39.96259098(22)	觀測上穩定^{[n 5]}			0+	0.96941(156)	0.96933–0.96947
41 Ca	20	21	40.96227806(26)	1.02(7)×10⁵ y	ε	⁴¹K	7/2−	痕量^{[n 6]}
42 Ca	20	22	41.95861801(27)	穩定			0+	0.00647(23)	0.00646–0.00648
43 Ca	20	23	42.9587666(3)	穩定			7/2−	0.00135(10)	0.00135–0.00135
44 Ca	20	24	43.9554818(4)	穩定			0+	0.02086(110)	0.02082–0.02092
45 Ca	20	25	44.9561866(4)	162.67(25) d	β⁻	⁴⁵Sc	7/2−
46 Ca	20	26	45.9536926(24)	觀測上穩定^{[n 7]}			0+	4(3)×10⁻⁵	4×10⁻⁵–4×10⁻⁵
47 Ca	20	27	46.9545460(24)	4.536(3) d	β⁻	⁴⁷Sc	7/2−
48 Ca （英语：Calcium-48）^{[n 8]}	20	28	47.952534(4)	43(38)×10¹⁸ y	β⁻β⁻^{[n 9]}	⁴⁸Ti	0+	0.00187(21)	0.00186–0.00188
49 Ca	20	29	48.955674(4)	8.718(6) min	β⁻	⁴⁹Sc	3/2−
50 Ca	20	30	49.957519(10)	13.9(6) s	β⁻	⁵⁰Sc	0+
51 Ca	20	31	50.9615(1)	10.0(8) s	β⁻ (>99.9%)	⁵¹Sc	(3/2−)#
51 Ca	20	31	50.9615(1)	10.0(8) s	β⁻, n (<.1%)	⁵⁰Sc	(3/2−)#
52 Ca	20	32	51.96510(75)	4.6(3) s	β⁻ (98%)	⁵²Sc	0+
52 Ca	20	32	51.96510(75)	4.6(3) s	β⁻, n (2%)	⁵¹Sc	0+
53 Ca	20	33	52.97005(54)#	90(15) ms	β⁻ (70%)	⁵³Sc	3/2−#
53 Ca	20	33	52.97005(54)#	90(15) ms	β⁻, n (30%)	⁵²Sc	3/2−#
54 Ca	20	34	53.97435(75)#	50# ms [>300 ns]	β⁻, n	⁵³Sc	0+
54 Ca	20	34	53.97435(75)#	50# ms [>300 ns]	β⁻	⁵⁴Sc	0+
55 Ca	20	35	54.98055(75)#	30# ms [>300 ns]	β⁻	⁵⁵Sc	5/2−#
56 Ca	20	36	55.98557(97)#	10# ms [>300 ns]	β⁻	⁵⁶Sc	0+
57 Ca	20	37	56.99236(107)#	5# ms	β⁻	⁵⁷Sc	5/2−#
57 Ca	20	37	56.99236(107)#	5# ms	β⁻, n	⁵⁶Sc	5/2−#
58 Ca	20	38	(57.962133)#				(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	→
鉀的同位素	鈣的同位素	鈧的同位素

註釋

^ Bold for isotopes with half-lives longer than the age of the universe (nearly stable)
^ Abbreviations:
EC: 电子俘获
^ Bold for stable isotopes
^ Heaviest nuclide with equal numbers of protons and neutrons with no observed decay
^ Believed to undergo double electron capture to ⁴⁰Ar with a half-life no less than 5.9×10²¹ a
^ Cosmogenic nuclide（英语：Cosmogenic nuclide）
^ Believed to undergo β⁻β⁻ decay to ⁴⁶Ti with a half-life no less than 2.8×10¹⁵ a
^ Primordial（英语：Primordial nuclide）放射性同位素
^ Lightest nuclide known to undergo 雙β衰變

参考文獻

^ Meija, Juris; et al. Atomic weights of the elements 2013 (IUPAC Technical Report). Pure and Applied Chemistry. 2016, 88 (3): 265–91. doi:10.1515/pac-2015-0305.
^ Universal Nuclide Chart. nucleonica. [2015-09-11]. （原始内容存档于2017-02-19）.

Isotope masses from Ame2003 Atomic Mass Evaluation by G. Audi, A.H. Wapstra, C. Thibault, J. Blachot and O. Bersillon in Nuclear Physics A729 (2003).
Isotopic compositions and standard atomic masses from Atomic weights of the elements. Review 2000 (IUPAC Technical Report) （页面存档备份，存于互联网档案馆）. Pure Appl. Chem. Vol. 75, No. 6, pp. 683-800, (2003) and Atomic Weights Revised (2005) （页面存档备份，存于互联网档案馆）.
Half-life, spin, and isomer data selected from these sources. Editing notes on this article's talk page.
- Audi, Bersillon, Blachot, Wapstra. The Nubase2003 evaluation of nuclear and decay properties （页面存档备份，存于互联网档案馆）, Nuc. Phys. A 729, pp. 3-128 (2003).
- National Nuclear Data Center, Brookhaven National Laboratory. Information extracted from the NuDat 2.1 database （页面存档备份，存于互联网档案馆） (retrieved Sept. 2005).
- David R. Lide (ed.), Norman E. Holden in CRC Handbook of Chemistry and Physics, 85th Edition, online version. CRC Press. Boca Raton, Florida (2005). Section 11, Table of the Isotopes.

[2] Bold for isotopes with half-lives longer than the age of the universe (nearly stable)

[4] Abbreviations:
EC: 电子俘获

[5] Bold for stable isotopes

[6] Heaviest nuclide with equal numbers of protons and neutrons with no observed decay

[7] Believed to undergo double electron capture to ⁴⁰Ar with a half-life no less than 5.9×10²¹ a

[8] Cosmogenic nuclide（英语：Cosmogenic nuclide）

[9] Believed to undergo β⁻β⁻ decay to ⁴⁶Ti with a half-life no less than 2.8×10¹⁵ a

[PN-10] Primordial（英语：Primordial nuclide）放射性同位素

[11] Lightest nuclide known to undergo 雙β衰變

[CIAAW2013-1] Meija, Juris; et al. Atomic weights of the elements 2013 (IUPAC Technical Report). Pure and Applied Chemistry. 2016, 88 (3): 265–91. doi:10.1515/pac-2015-0305.

[3] Universal Nuclide Chart. nucleonica. [2015-09-11]. （原始内容存档于2017-02-19）.

[1]

[n 1]

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