7440-11-1 Usage
History
Different sources of media describe the History of 7440-11-1 differently. You can refer to the following data:
1. The element first was made by Ghiorso, Harvey, Choppin, Thompson, and Seaborg in 1955 in Berkeley, California. It was synthesized by bombardment of einsteinium-253 with alpha particles of 41 MeV energy in a 60-inch cyclotron. The element was named Mendelevium in honor of Russian chemist Dimitri Mendeleev. Mendelevium –258 isotope with a half-life of 60 days was discovered in 1967. The element has no commercial use except in research to synthesize isotopes of other transuranium elements.
2. The element name of Md derives from the Russian chemist “Dimitrii Mendeleev” who developed the Periodic Table of the chemical elements. Credit for the first synthesis of this element is given American chemists Albert Ghiorso, Bernard G. Harvey, Gregory R. Choppin, and Stanley G. Thompson at the University of California lab in Berkeley, California under Glenn T. Seaborg in 1958, who used the nuclear reaction 253Es(4He, 2n) 255Md and the nuclear reaction 253Es (4He, n) 256Md. The longest half-life associated with this unstable element is 51 day 258Md.
Synthesis
Mendelevium was synthesized first by bombarding Einstein-253 with helium ions. The nuclear reaction is:
All isotopes of medelevium have been synthesized by other nuclear reactions since its discovery. They are prepared by bombarding uranium, einsteinium, and californium isotopes with heavy ions, such as boron-11, carbon12 and carbon-13.
For example, uranium-238 when bombarded with fluorine-19 produced Md252. Also, certain nuclear reactions carried out by heavy ion projectiles involve ‘stripping’ reactions in which some protons and neutrons may transfer from the projectiles onto the target nucleus, but the latter might not capture the projectile heavy ion.
Chemical Properties
discovered in 1955 by Ghiorso and colleagues at Lawrence Berkeley Laboratory; preparation: bombardment of 253Es with He ions [KIR78]
Check Digit Verification of cas no
The CAS Registry Mumber 7440-11-1 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 7,4,4 and 0 respectively; the second part has 2 digits, 1 and 1 respectively.
Calculate Digit Verification of CAS Registry Number 7440-11:
(6*7)+(5*4)+(4*4)+(3*0)+(2*1)+(1*1)=81
81 % 10 = 1
So 7440-11-1 is a valid CAS Registry Number.
InChI:InChI=1/Md
