Isotopes of mendelevium

Last updated
Isotopes of mendelevium  (101Md)
Main isotopes [1] Decay
abun­dance half-life (t1/2) mode pro­duct
256Md synth 1.17 h ε 256Fm
257Mdsynth5.52 hε 257Fm
α 253Es
SF –
258Mdsynth51.5 dα 254Es
ε 258Fm
β− 258No
259Mdsynth1.60 hSF–
α 255Es
260Mdsynth31.8 dSF–
α 256Es
ε 260Fm
β− 260No

Mendelevium (101Md) is a synthetic element, and thus a standard atomic weight cannot be given. Like all artificial elements, it has no stable isotopes. The first isotope to be synthesized was 256Md (which was also the first isotope of any element produced one atom at a time) in 1955. There are 17 known radioisotopes, ranging in atomic mass from 244Md to 260Md, and 5 isomers. The longest-lived isotope is 258Md with a half-life of 51.3 days, and the longest-lived isomer is 258mMd with a half-life of 57 minutes.

Contents

List of isotopes

Nuclide
[n 1] 		Z N Isotopic mass (Da)
[n 2] [n 3] 		Half-life
Decay
mode
[n 4] 		Daughter
isotope
Spin and
parity
[n 5] [n 6]
Excitation energy [n 6]
244Md [2] 1011430.30+0.19
−0.09 s		 α 240Es
245Md [2] 101144245.08081(33)#0.33+0.15
−0.08 s		α241Es7/2−#
β+ (rare)245Fm
245mMd200(100)# keV0.90(25) ms SF (various)1/2−#
246Md [3] 101145246.08171(28)#0.9(2) sα242Es
β+?246Fm
246mMd4.4(8) sβ+ (>67%)246Fm
α (<23%)242Es
β+, SF (>10%)(various)
247Md [4] 101146247.08152(22)#1.20(12) sα (99.14%)243Es(7/2−)
SF (0.86%)(various)
β+?247Fm
247mMd153 keV0.23(3) sα (80%)243Es(1/2−)
SF (20%)(various)
248Md101147248.08282(26)#7(3) sβ+ (80%)248Fm
α (20%)244Es
β+, SF (.05%)(various)
249Md [5] 101148249.08291(22)#26(1) sα (75%)245Es(7/2−)
β+ (25%)249Fm
249mMd [6] 100(100)# keV1.5+1.2
−0.5 s		α245Es(1/2−)
250Md [7] 101149250.08442(32)#54(4) sβ+ (93.0%)250Fm
α (7.0%)246Es
β+, SF (0.026%)(various)
251Md [8] 101150251.084774(20)4.27(26) minβ+ (90%)251Fm(7/2−)
α (10%)247Es
252Md101151252.08643(14)#2.3(8) minβ+252Fm
α (rare) [9] 248Es
253Md101152253.08714(3)#12(8) min
[6.4+11.6
−3.6 min]		β+ (~99%) [10] 253Fm(7/2−)
α (~1%)249Es
254Md101153254.08959(11)#10(3) minβ+254Fm(0−)
α (rare)250Es
254mMd50(100)# keV28(8) minβ+254Fm(3−)
α (rare)250Es
255Md101154255.091084(7)27(2) minβ+ (92%)255Fm(7/2−)
α (8%)251Es
SF (.15%)(various)
256Md101155256.09389(13)#77(2) minβ+ (89%)256Fm(1−)
α (11%)252Es
257Md101156257.0955424(29)5.52(5) h EC (84.8%)257Fm(7/2−)
α (15.2%)253Es
SF (rare)(various)
258Md [11] 101157258.098431(5)51.59(29) dα254Es(8−)#
β− (<0.0015%)258No
β+ (<0.0015%)258Fm
258mMd0(200)# keV57.0(9) minEC258Fm1−#
SF (<15%)(various)
α (<1.2%)254Es
β− (rare)258No
259Md [n 7] [12] 101158259.10051(22)#1.60(6) hSF(various)7/2−#
α (rare)255Es
260Md [13] 101159260.10365(34)#27.8(8) dSF(various)
α (<5%)256Es
EC (<5%)260Fm
β− (<3.5%)260No
This table header & footer:
  1. ↑ mMd – Excited nuclear isomer.
  2. ↑ ( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
  3. ↑ # – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).
  4. ↑ Modes of decay:
    EC: Electron capture
    SF: Spontaneous fission
  5. ↑ ( ) spin value – Indicates spin with weak assignment arguments.
  6. 1 2 # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
  7. ↑ Not directly synthesized, occurs as decay product of 259No

Chronology of isotope discovery

IsotopeDiscoveredReaction
244Md2020209Bi(40Ar,5n)
245Md1996209Bi(40Ar,4n)
246Md1996209Bi(40Ar,3n)
247Md1981209Bi(40Ar,2n)
248Md1973241Am(12C,5n)
249Md1973241Am(12C,4n)
250Md1973243Am(12C,5n), 243Am(13C,6n)
251Md1973243Am(12C,4n), 243Am(13C,5n)
252Md1973243Am(13C,4n)
253Md1992243Am(13C,3n)
254Md1970253Es(α,3n)
255Md1958253Es(α,2n)
256Md1955253Es(α,n)
257Md1964252Cf(11B,α2n)
258Md1970255Es(α,n)
259Md1982248Cm(18O,α3n) [14]
260Md1989254Es+18O, 22Ne — transfer

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References

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  2. 1 2 Khuyagbaatar, J.; Albers, H. M.; Block, M.; Brand, H.; Cantemir, R. A.; Di Nitto, A.; Düllmann, Ch. E.; Götz, M.; Götz, S.; Heßberger, F. P.; Jäger, E.; Kindler, B.; Kratz, J. V.; Krier, J.; Kurz, N.; Lommel, B.; Lens, L.; Mistry, A.; Schausten, B.; Uusitalo, J.; Yakushev, A. (1 October 2020). "Search for Electron-Capture Delayed Fission in the New Isotope 244Md". Physical Review Letters. 125 (14): 142504. Bibcode:2020PhRvL.125n2504K. doi:10.1103/PhysRevLett.125.142504. PMID   33064498. S2CID   223546973.
  3. ↑ Antalic, S.; Heßberger, F. P.; Hofmann, S.; Ackermann, D.; Heinz, S.; Kindler, B.; Kojouharov, I.; Kuusiniemi, P.; Leino, M.; Lommel, B.; Mann, R.; Šáro, Š. (20 November 2009). "Studies of neutron-deficient mendelevium isotopes at SHIP". The European Physical Journal A. 43 (1): 35. doi:10.1140/epja/i2009-10896-0. ISSN   1434-601X. S2CID   121963345.
  4. ↑ Heßberger, F. P.; Antalic, S.; Giacoppo, F.; Andel, B.; Ackermann, D.; Block, M.; Heinz, S.; Khuyagbaatar, J.; Kojouharov, I.; Venhart, M. (25 January 2022). "Alpha-gamma decay studies of 247Md". The European Physical Journal A. 58 (1): 11. Bibcode:2022EPJA...58...11H. doi: 10.1140/epja/s10050-022-00663-4 . ISSN   1434-601X. S2CID   246281669.
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  6. ↑ Heßberger, F.P.; Hofmann, S.; Ackermann, D.; Ninov, V.; Leino, M.; Münzenberg, G.; Saro, S.; Lavrentev, A.; Popeko, A.G.; Yeremin, A.V.; Stodel, Ch. (1 September 2001). "Decay properties of neutron-deficient isotopes 256, 257Db, 255Rf, 252, 253Lr". The European Physical Journal A - Hadrons and Nuclei. 12 (1): 57–67. Bibcode:2001EPJA...12...57H. doi:10.1007/s100500170039. ISSN   1434-601X. S2CID   117896888 . Retrieved 1 July 2023.
  7. ↑ Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (1 March 2021). "The NUBASE2020 evaluation of nuclear physics properties *". Chinese Physics C, High Energy Physics and Nuclear Physics. 45 (3): 030001. Bibcode:2021ChPhC..45c0001K. doi: 10.1088/1674-1137/abddae . ISSN   1674-1137. OSTI   1774641. S2CID   233794940.
  8. ↑ Chatillon, A.; Theisen, Ch.; Greenlees, P. T.; Auger, G.; Bastin, J. E.; Bouchez, E.; Bouriquet, B.; Casandjian, J. M.; Cee, R.; Clément, E.; Dayras, R.; de France, G.; de Toureil, R.; Eeckhaudt, S.; Görgen, A.; Grahn, T.; Grévy, S.; Hauschild, K.; Herzberg, R. -D.; Ikin, P. J. C.; Jones, G. D.; Jones, P.; Julin, R.; Juutinen, S.; Kettunen, H.; Korichi, A.; Korten, W.; Le Coz, Y.; Leino, M.; Lopez-Martens, A.; Lukyanov, S. M.; Penionzhkevich, Yu. E.; Perkowski, J.; Pritchard, A.; Rahkila, P.; Rejmund, M.; Saren, J.; Scholey, C.; Siem, S.; Saint-Laurent, M. G.; Simenel, C.; Sobolev, Yu. G.; Stodel, Ch.; Uusitalo, J.; Villari, A.; Bender, M.; Bonche, P.; Heenen, P. -H. (1 November 2006). "Spectroscopy and single-particle structure of the odd- Z heavy elements 255Lr, 251Md and 247Es". The European Physical Journal A - Hadrons and Nuclei. 30 (2): 397–411. Bibcode:2006EPJA...30..397C. doi:10.1140/epja/i2006-10134-5. ISSN   1434-601X. S2CID   123346991 . Retrieved 1 July 2023.
  9. ↑ Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (1 March 2021). "The NUBASE2020 evaluation of nuclear physics properties *". Chinese Physics C, High Energy Physics and Nuclear Physics. 45 (3): 030001. Bibcode:2021ChPhC..45c0001K. doi: 10.1088/1674-1137/abddae . ISSN   1674-1137. OSTI   1774641. S2CID   233794940.
  10. ↑ Antalic, S.; Heßberger, F. P.; Ackermann, D.; Heinz, S.; Hofmann, S.; Kalaninová, Z.; Kindler, B.; Khuyagbaatar, J.; Kojouharov, I.; Kuusiniemi, P.; Leino, M.; Lommel, B.; Mann, R.; Nishio, K.; Šáro, Š.; Streicher, B.; Sulignano, B.; Venhart, M. (20 May 2011). "Isomeric states in 253No and 253Fm". The European Physical Journal A. 47 (5): 62. Bibcode:2011EPJA...47...62A. doi:10.1140/epja/i2011-11062-y. ISSN   1434-601X. S2CID   121080273.
  11. ↑ Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (1 March 2021). "The NUBASE2020 evaluation of nuclear physics properties *". Chinese Physics C, High Energy Physics and Nuclear Physics. 45 (3): 030001. Bibcode:2021ChPhC..45c0001K. doi: 10.1088/1674-1137/abddae . ISSN   1674-1137. OSTI   1774641. S2CID   233794940.
  12. ↑ Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (1 March 2021). "The NUBASE2020 evaluation of nuclear physics properties *". Chinese Physics C, High Energy Physics and Nuclear Physics. 45 (3): 030001. Bibcode:2021ChPhC..45c0001K. doi: 10.1088/1674-1137/abddae . ISSN   1674-1137. OSTI   1774641. S2CID   233794940.
  13. ↑ Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (1 March 2021). "The NUBASE2020 evaluation of nuclear physics properties *". Chinese Physics C, High Energy Physics and Nuclear Physics. 45 (3): 030001. Bibcode:2021ChPhC..45c0001K. doi: 10.1088/1674-1137/abddae . ISSN   1674-1137. OSTI   1774641. S2CID   233794940.
  14. ↑ see nobelium
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