Talk:Isotopes of americium/Archive 1

Archive 1

Data 2003

This article is part of Wikipedia:Wikiproject Isotopes. Please keep style and phrasings consistent across the set of pages. For later reference and improved reliability, data from all considered multiple sources is collected here. References are denoted by these letters:

• (A) G. Audi, O. Bersillon, J. Blachot, A.H. Wapstra. The Nubase2003 evaluation of nuclear and decay properties, Nuc. Phys. A 729, pp. 3-128 (2003). — Where this source indicates a speculative value, the # mark is also applied to values with weak assignment arguments from other sources, if grouped together. An asterisk after the A means that a comment of some importance may be available in the original.
• (B) National Nuclear Data Center, Brookhaven National Laboratory, information extracted from the NuDat 2.1 database. (Retrieved Sept. 2005, from the code of the popup boxes).
• (C) 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. — The CRC uses rounded numbers with implied uncertainties, where this concurs with the range of another source it is treated as exactly equal in this comparison.
• (D) More specific level data from reference B's Levels and Gammas database.
• (E) Same as B but excitation energy replaced with that from D.

  Z   N refs symbol   half-life                   spin              excitation energy
 95 136 A   |Am-231  |30# s                      |
 95 136 B   |Am-231  |~10 s                      |
 95 137 A   |Am-232  |1.31(4) min                |
 95 137 B   |Am-232  |79(2) s                    |
 95 137 C   |Am-232  |0.9 min                    |
 95 138 AB  |Am-233  |3.2(8) min                 |
 95 138 C   |Am-233  |~3.2 min                   |
 95 139 ABC |Am-234  |2.32(8) min                |
 95 140 A   |Am-235  |9.9(5) min                 |5/2-#
 95 140 B   |Am-235  |10.3(6) min                |
 95 140 C   |Am-235  |~15 min                    |
 95 141 A   |Am-236  |30# min                    |
 95 141 B   |Am-236  |3.6(1) min                 |
 95 141 C   |Am-236  |54. s                      |
 95 142 AB  |Am-237  |73.0(10) min               |5/2(-)
 95 142 C   |Am-237  |1.22 h                     |(5/2-)
 95 143 ABC |Am-238  |98(2) min                  |1+
 95 143 A   |Am-238m |35(10) µs                  |                 |2500(200)# keV
 95 143 D   |Am-238m |35 µs                      |                 |~2500 keV
 95 144 AB  |Am-239  |11.9(1) h                  |(5/2)-
 95 144 C   |Am-239  |11.9 h                     |5/2-
 95 144 AD  |Am-239m |163(12) ns                 |(7/2+)           |2500(200) keV
 95 145 ABC |Am-240  |50.8(3) h                  |(3-)
 95 146 AB  |Am-241  |432.2(7) a                 |5/2-
 95 146 C   |Am-241  |432.7 a                    |5/2-
 95 146 A   |Am-241m |1.5 µs                     |                 |2200(100) keV
 95 146 D   |Am-241m |1.2(3) µs                  |                 |~2200 keV
 95 147 ABC |Am-242  |16.02(2) h                 |1-
 95 147 AE  |Am-242m1|141(2) a                   |5-               |48.60(5) keV
 95 147 C   |Am-242m1|141. a                     |5-
 95 147 AE  |Am-242m2|14.0(10) ms                |(2+,3-)          |2200(80) keV
 95 148 A   |Am-243  |7.37(4)E+3 a               |5/2-
 95 148 B   |Am-243  |7370(40) a                 |5/2-
 95 148 C   |Am-243  |7.37E+3 a                  |5/2-
 95 149 AB  |Am-244  |10.1(1) h                  |(6-)#
 95 149 C   |Am-244  |10.1 h                     |
 95 149 A   |Am-244m |26(1) min                  |1+               |88.6(17) keV
 95 149 E   |Am-244m |26(1) min                  |1+               |86.1(10) keV
 95 149 C   |Am-244m |~26. min                   |(1-)
 95 149 E   |Am-244m |0.90(15) ms                |                 |0+X keV
 95 149 D   |Am-244m |~6.5 µs                    |                 |0+Y keV
 95 150 AB  |Am-245  |2.05(1) h                  |(5/2)+
 95 150 C   |Am-245  |2.05 h                     |(5/2+)
 95 151 ABC |Am-246  |39(3) min                  |(7-)
 95 151 A   |Am-246m1|25.0(2) min                |2(-)             |30(10) keV
 95 151 E   |Am-246m1|25.0(2) min                |2(-)             |0+X keV
 95 151 C   |Am-246m1|25.0 min                   |2-
 95 151 D   |Am-246m2|73(10) µs                  |                 |~2000 keV
 95 152 AB  |Am-247  |23.0(13) min               |(5/2)#
 95 152 C   |Am-247  |22. min                    |
 95 153 A   |Am-248  |3# min                     |
 95 153 B   |Am-248  |~10 min                    |
 95 154 A   |Am-249  |1# min                     |
 95 154 B   |Am-249  |~2 min                     |

Femto 11:24, 17 November 2005 (UTC)

Talk

The chart in the upper right corner of the page is confusing.

1. It does not have a title.
2. Rows 2 through 6 under "Fission Products" shows "No fission product has halflife 102 to 2×105 years", but Americium 241 emits alpha particles. Isn't alpha decay a form of fission?
3. Some half lives have units, some don't, and there is no key as to what the abreviations stand for. Some places seem to use a (presumably for annum/annual), others use y (presumably for years).
4. Is there some order for grouping elements on the left hand side of the chart? It seems pretty random to me.
5. What are the notations in the spaces on the left hand side of the chart that are not occupied by elements?

In any case, what is the decay path of Americium 241?

The use of the pound sign (#) in the TABLE is also a little odd. I would expect to find an asterisk, or a directive [See Note 1], and I would expect to see it at the end of the entry, not in the middle, like 1# min. c.pergiel@gmail.com (71.117.211.59 (talk) 05:12, 3 November 2009 (UTC))

1. The three titles in the first row make it clear it is a table of actinides and fission products and their halflives. These two categories of radioactive nuclides are often compared in discussion of various nuclear fuel cycles.
2. No, alpha decay is not considered a form of nuclear fission, which is splitting into more equally sized parts. And the nuclides on the left are not fission products, which are on the right and labeled.
3. No visible places use "a" for year, are you looking at source which is commented out? Halflives are in years, kiloyears, million years, and billion years, all commonly used abbreviations. To keep the column from getting too wide, the unit is sometimes not specified if it is the same as the previous row. The halflife ranges are monotonically increasing, with each change in unit being a multiplication by 1000.
4. They are grouped by decay series horizontally and halflife vertically.
5. The notations are links to the individual decay series and clicking and reading would have answered your previous question.

The decay path of Am-241 is alpha decay to Np-237 which has a much longer halflife, eventually alpha decaying to U-233, Th-229 and further. Note all of these are in the same column, which is an advantage of the arrangement by decay series; you only have to search the same column for another actinide with mass 4 less, not the whole table.

I did not make the other table. I also find the pound sign unusual for a footnote, but at least it is comprehensible if you keep reading. --JWB (talk) 07:26, 3 November 2009 (UTC)