Silicon
Silicon is a chemical element with the symbol Si and atomic number 14. It is a hard, brittle crystalline solid with a blue-grey metallic luster, and is a tetravalent metalloid and semiconductor. It is a member of group 14 in the periodic ta ...
(
14Si) has 23 known
isotope
Isotopes are two or more types of atoms that have the same atomic number (number of protons in their nuclei) and position in the periodic table (and hence belong to the same chemical element), and that differ in nucleon numbers (mass numb ...
s, with
mass number
The mass number (symbol ''A'', from the German word ''Atomgewicht'' tomic weight, also called atomic mass number or nucleon number, is the total number of protons and neutrons (together known as nucleons) in an atomic nucleus. It is approxima ...
s ranging from 22 to 44.
28Si (the most abundant isotope, at 92.23%),
29Si (4.67%), and
30Si (3.1%) are stable. The longest-lived radioisotope is
32Si, which is produced by
cosmic ray spallation
Cosmic ray spallation, also known as the x-process, is a set of naturally occurring nuclear reactions causing nucleosynthesis; it refers to the formation of chemical elements from the impact of cosmic rays on an object. Cosmic rays are highly ener ...
of
argon
Argon is a chemical element with the symbol Ar and atomic number 18. It is in group 18 of the periodic table and is a noble gas. Argon is the third-most abundant gas in Earth's atmosphere, at 0.934% (9340 ppmv). It is more than twice as ...
. Its
half-life
Half-life (symbol ) is the time required for a quantity (of substance) to reduce to half of its initial value. The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay or how long stable at ...
has been determined to be approximately 150 years (with
decay energy
The decay energy is the energy change of a nucleus having undergone a radioactive decay. Radioactive decay is the process in which an unstable atomic nucleus loses energy by emitting ionizing particles and radiation. This decay, or loss of energy ...
0.21 MeV), and it decays by
beta emission
In nuclear physics, beta decay (β-decay) is a type of radioactive decay in which a beta particle (fast energetic electron or positron) is emitted from an atomic nucleus, transforming the original nuclide to an isobar of that nuclide. For exam ...
to
32 P (which has a 14.28-day half-life) and then to
32 S. After
32Si,
31Si has the second longest half-life at 157.3 minutes. All others have half-lives under 7 seconds.
List of isotopes
, -
, rowspan=2,
22Si
, rowspan=2 style="text-align:right" , 14
, rowspan=2 style="text-align:right" , 8
, rowspan=2, 22.03579(54)#
, rowspan=2, 29(2) ms
,
β+ (67.6%)
,
22Al
, rowspan=2, 0+
, rowspan=2,
, rowspan=2,
, -
, β
+,
p (32.4%)
,
21Mg
, -
, rowspan=2,
23Si
, rowspan=2 style="text-align:right" , 14
, rowspan=2 style="text-align:right" , 9
, rowspan=2, 23.02544(54)#
, rowspan=2, 42.3(4) ms
, β
+, p (88%)
,
22Mg
, rowspan=2, 3/2+#
, rowspan=2,
, rowspan=2,
, -
, β
+ (12%)
,
23Al
, -
, rowspan=2,
24Si
, rowspan=2 style="text-align:right" , 14
, rowspan=2 style="text-align:right" , 10
, rowspan=2, 24.011535(21)
, rowspan=2, 140(8) ms
, β
+ (62.4%)
,
24Al
, rowspan=2, 0+
, rowspan=2,
, rowspan=2,
, -
, β
+, p (37.6%)
,
23Mg
, -
, rowspan=2,
25Si
, rowspan=2 style="text-align:right" , 14
, rowspan=2 style="text-align:right" , 11
, rowspan=2, 25.004109(11)
, rowspan=2, 220(3) ms
, β
+ (64.8%)
,
25Al
, rowspan=2, 5/2+
, rowspan=2,
, rowspan=2,
, -
, β
+, p (35.2%)
,
24Mg
, -
,
26Si
, style="text-align:right" , 14
, style="text-align:right" , 12
, 25.9923338(12)
, 2.2453(7) s
, β
+
,
26Al
, 0+
,
,
, -
,
27Si
, style="text-align:right" , 14
, style="text-align:right" , 13
, 26.98670469(12)
, 4.15(4) s
, β
+
,
27Al
, 5/2+
,
,
, -
,
28Si
, style="text-align:right" , 14
, style="text-align:right" , 14
, 27.9769265350(5)
, colspan=3 align=center, Stable
, 0+
, 0.92223(19)
, 0.92205–0.92241
, -
,
29Si
, style="text-align:right" , 14
, style="text-align:right" , 15
, 28.9764946653(6)
, colspan=3 align=center, Stable
, 1/2+
, 0.04685(8)
, 0.04678–0.04692
, -
,
30Si
, style="text-align:right" , 14
, style="text-align:right" , 16
, 29.973770137(23)
, colspan=3 align=center, Stable
, 0+
, 0.03092(11)
, 0.03082–0.03102
, -
,
31Si
, style="text-align:right" , 14
, style="text-align:right" , 17
, 30.97536319(5)
, 157.36(26) min
, β
−
,
31P
, 3/2+
,
,
, -
,
32Si
, style="text-align:right" , 14
, style="text-align:right" , 18
, 31.9741515(3)
, 153(19) y
, β
−
,
32P
, 0+
,
trace
Trace may refer to:
Arts and entertainment Music
* ''Trace'' (Son Volt album), 1995
* ''Trace'' (Died Pretty album), 1993
* Trace (band), a Dutch progressive rock band
* ''The Trace'' (album)
Other uses in arts and entertainment
* ''Trace'' ...
,
cosmogenic
Cosmogenic nuclides (or cosmogenic isotopes) are rare nuclides (isotopes) created when a high-energy cosmic ray interacts with the nucleus of an ''in situ'' Solar System atom, causing nucleons (protons and neutrons) to be expelled from the atom ...
, -
,
33Si
, style="text-align:right" , 14
, style="text-align:right" , 19
, 32.9779770(8)
, 6.18(18) s
, β
−
,
33P
, (3/2+)
,
,
, -
,
34Si
, style="text-align:right" , 14
, style="text-align:right" , 20
, 33.978575(15)
, 2.77(20) s
, β
−
,
34P
, 0+
,
,
, -
, style="text-indent:1em" ,
34mSi
, colspan=3 style="text-indent:2em" , 4256.1(4) keV
, <210 ns
, IT
,
34Si
, (3−)
,
,
, -
,
35Si
, style="text-align:right" , 14
, style="text-align:right" , 21
, 34.98455(4)
, 780(120) ms
, β
− (94.74%)
,
35P
, 7/2−#
,
,
, -
, rowspan=2,
36Si
, rowspan=2 style="text-align:right" , 14
, rowspan=2 style="text-align:right" , 22
, rowspan=2, 35.98665(8)
, rowspan=2, 450(60) ms
, β
− (87.5%)
,
36P
, rowspan=2, 0+
, rowspan=2,
, rowspan=2,
, -
, β
−,
n (12.5%)
,
35P
, -
, rowspan=2,
37Si
, rowspan=2 style="text-align:right" , 14
, rowspan=2 style="text-align:right" , 23
, rowspan=2, 36.99295(12)
, rowspan=2, 90(60) ms
, β
− (83%)
,
37P
, rowspan=2, (7/2−)#
, rowspan=2,
, rowspan=2,
, -
, β
−, n (17%)
,
36P
, -
, rowspan=2,
38Si
, rowspan=2 style="text-align:right" , 14
, rowspan=2 style="text-align:right" , 24
, rowspan=2, 37.99552(11)
, rowspan=2, 90# ms
1 μs, β
−, n
,
37P
, rowspan=2, 0+
, rowspan=2,
, rowspan=2,
, -
, β
−
,
38P
, -
,
39Si
, style="text-align:right" , 14
, style="text-align:right" , 25
, 39.00249(15)
, 47.5(20) ms
, β
−
,
39P
, 7/2−#
,
,
, -
,
40Si
, style="text-align:right" , 14
, style="text-align:right" , 26
, 40.00583(37)
, 33.0(10) ms
, β
−
,
40P
, 0+
,
,
, -
,
41Si
, style="text-align:right" , 14
, style="text-align:right" , 27
, 41.01301(60)
, 20.0(25) ms
, β
−
,
41P
, 7/2−#
,
,
, -
,
42Si
, style="text-align:right" , 14
, style="text-align:right" , 28
, 42.01768(54)#
, 12.5(35) ms
, β
−
,
42P
, 0+
,
,
, -
,
43Si
, style="text-align:right" , 14
, style="text-align:right" , 29
, 43.02480(64)#
, 15# ms
260 ns,
,
, 3/2−#
,
,
, -
,
44Si
, style="text-align:right" , 14
, style="text-align:right" , 30
, 44.03147(54)#
, 4# ms
360 ns,
,
, 0+
,
,
, -
,
45Si?
[The existence of this isotope has not been confirmed experimentally; given data is inferred or estimated from periodic trends.]
, style="text-align:right" , 14
, style="text-align:right" , 31
, 45.03982(64)#
, 4# ms
,
,
, 3/2−#
,
,
References
External links
Silicon isotopes data from ''The Berkeley Laboratory Isotopes Project's''
{{Navbox element isotopes
Silicon
Silicon
Silicon is a chemical element with the symbol Si and atomic number 14. It is a hard, brittle crystalline solid with a blue-grey metallic luster, and is a tetravalent metalloid and semiconductor. It is a member of group 14 in the periodic ta ...