Mendelevium

Mendelevium, ₁₀₁Md
Mendelevium
Pronunciation	/ˌmɛndəˈliːviəm/; (MEN-də-LEE-vee-əm); /ˌmɛndəˈleɪviəm/; (MEN-də-LAY-vee-əm);
Mass number	[258]
Mendelevium in the periodic table
	fermium ← mendelevium → nobelium
Atomic number (Z)	101
Group	f-block groups (no number)
Period	period 7
Block	f-block
Electron configuration	[Rn] 5f13 7s2
Electrons per shell	2, 8, 18, 32, 31, 8, 2
Physical properties
Phase at STP	solid (predicted)
Melting point	1100 K (827 °C, 1521 °F) (predicted)
Density (near r.t.)	10.3(7) g/cm3 (predicted)
Atomic properties
Oxidation states	+2, +3
Electronegativity	Pauling scale: 1.3
Ionization energies	1st: 636 kJ/mol ; ;
Other properties
Natural occurrence	synthetic
Crystal structure	face-centered cubic (fcc) ; (predicted)
CAS Number	7440-11-1
History
Naming	after Dmitri Mendeleev
Discovery	Lawrence Berkeley National Laboratory (1955)
Isotopes of mendelevium v; e;
α	253Es
SF	–
ε	258Fm
β−	258No
α	255Es
α	256Es
ε	260Fm
β−	260No
	Category: Mendelevium; view; talk; edit; \| references

Mendelevium (pronounced /ˌmɛndəˈlɛviəm/) is a synthetic, radioactive transuranic chemical element with the symbol Md and the atomic number 101.

History

Mendelevium was the ninth transuranic element to be synthesized. It was first synthesized by Albert Ghiorso, Glenn T. Seaborg, Gregory Robert Choppin, Bernard G. Harvey, and team leader Stanley G. Thompson in early 1955 at the University of California, Berkeley. It was named after Dmitri Mendeleev, the creator of the periodic table, and it used to have the symbol Mv but it was later changed in 1957.

Chemistry

Mendelevium is created by bombarding einsteinium with alpha particles. Mendelevium is a metallic element whose most stable isotope is Md-258 with a half-life of 51.6 days. Mendelevium's chemistry is not yet well known, but it can form some complex compounds.

forcefully combining and was named after Dmitri Mendeleev, the creator of the Periodic Table.

Health Effects

The International Commission on Radiological Protection has set annual exposure limits for the most stable isotope. For mendelevium-258, the ingestion limit was set at 9×10⁵ becquerels (1 Bq = 1 decay per second), and given the half-life of this isotope, this is only 2.48 ng (nanograms). The inhalation limit is at 6000 Bq or 16.5 pg (picogram).

Other website

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1 2 Fournier, Jean-Marc (1976). "Bonding and the electronic structure of the actinide metals". Journal of Physics and Chemistry of Solids. 37 (2): 235–244. Bibcode:1976JPCS...37..235F. doi:10.1016/0022-3697(76)90167-0.
↑ https://pubs.acs.org/doi/10.1021/jacs.8b09068
↑ Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae.

↑ The density is calculated from the predicted metallic radius (Silva 2006) and the predicted close-packed crystal structure (Fournier 1976).

[density-1] 1 2 Fournier, Jean-Marc (1976). "Bonding and the electronic structure of the actinide metals". Journal of Physics and Chemistry of Solids. 37 (2): 235–244. Bibcode:1976JPCS...37..235F. doi:10.1016/0022-3697(76)90167-0.

[3] ttps://pubs.acs.org/doi/10.1021/jacs.8b09068

[NUBASE2020-4] Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae.

[2] The density is calculated from the predicted metallic radius (Silva 2006) and the predicted close-packed crystal structure (Fournier 1976).