# Mendelevium: isotope data

## Naturally occurring isotopes

This table shows information about naturally occuring isotopes, their atomic masses, their natural abundances, their nuclear spins, and their magnetic moments. Further data for radioisotopes (radioactive isotopes) of mendelevium are listed (including any which occur naturally) below.
Isotope Mass / Da Natural abundance (atom %) Nuclear spin (I) Magnetic moment (μ/μN)
nil

In the above, the most intense ion is set to 100% since this corresponds best to the output from a mass spectrometer. This is not to be confused with the relative percentage isotope abundances which totals 100% for all the naturally occurring isotopes.

Further data for naturally occuring isotopes of mendelevium are listed above. This table gives information about some radiosotopes of mendelevium, their masses, their half-lives, their modes of decay, their nuclear spins, and their nuclear magnetic moments.
Isotope Mass / Da Half-life Mode of decay Nuclear spin Nuclear magnetic moment
255Md 255.09108 27 m α to 251Es; EC to 255Fm; SF 7/2
256Md 256.0941 1.3 h α to 252Es; EC to 256Fm; SF
257Md 257.09553 57 m α to 253Es; EC to 257Fm; SF 7/2
258Md 258.09857 (22) 51.5 d EC to 258Fm 8
259Md 259.1005 1.6 h α to 255Es; SF 7/2
260Md 260.104 32 d EC to 260Fm; α to 256Es; β- to 260No

## Sheffield ChemPuter isotope pattern calculator

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### References

1. Naturally occurring isotope abundances: Commission on Atomic Weights and Isotopic Abundances report for the International Union of Pure and Applied Chemistry in Isotopic Compositions of the Elements 1989, Pure and Applied Chemistry, 1998, 70, 217. [Copyright 1998 IUPAC]
2. For further information about radioisotopes see Jonghwa Chang's (Korea Atomic Energy Research Institute) Table of the Nuclides
3. Masses, nuclear spins, and magnetic moments: I. Mills, T. Cvitas, K. Homann, N. Kallay, and K. Kuchitsu in Quantities, Units and Symbols in Physical Chemistry, Blackwell Scientific Publications, Oxford, UK, 1988. [Copyright 1988 IUPAC]

## NMR Properties of mendelevium

Common reference compound: .

Isotope 1 Isotope 2 Isotope none Natural abundance /% 0 Spin (I) Frequency relative to 1H = 100 (MHz) Receptivity, DP, relative to 1H = 1.00 Receptivity, DC, relative to 13C = 1.00 Magnetogyric ratio, γ (107 rad T‑1 s-1) Magnetic moment, μ (μN) Nuclear quadrupole moment, Q/millibarn Line width factor, 1056 l (m4)

### References

1. R.K. Harris in Encyclopedia of Nuclear Magnetic Resonance, D.M. Granty and R.K. Harris, (eds.), vol. 5, John Wiley & Sons, Chichester, UK, 1996. I am grateful to Professor Robin Harris (University of Durham, UK) who provided much of the NMR data, which are copyright 1996 IUPAC, adapted from his contribution contained within this reference.
2. J. Mason in Multinuclear NMR, Plenum Press, New York, USA, 1987. Where given, data for certain radioactive nuclei are from this reference.
3. P. Pyykkö, Mol. Phys., 2008, 106, 1965-1974.
4. P. Pyykkö, Mol. Phys., 2001, 99, 1617-1629.
5. P. Pyykkö, Z. Naturforsch., 1992, 47a, 189. I am grateful to Professor Pekka Pyykkö (University of Helsinki, Finland) who provided the nuclear quadrupole moment data in this and the following two references.
6. D.R. Lide, (ed.), CRC Handbook of Chemistry and Physics 1999-2000 : A Ready-Reference Book of Chemical and Physical Data (CRC Handbook of Chemistry and Physics, CRC Press, Boca Raton, Florida, USA, 79th edition, 1998.
7. P. Pyykkö, personal communication, 1998, 204, 2008, 2010.

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