The spent nuclear fuel to which this process is applied consists primarily of certain very high atomic-weight ( actinoid or " actinide ") elements ( e. g., uranium ) along with smaller amounts of material composed of lighter atoms, notably the so-called fission products.

However, lawrencium is classified as an actinide element according to the IUPAC recommendations.

Although lutetium and lawrencium are in the d-block, they are not considered transition metals but a lanthanide and an actinide, respectively, according to IUPAC.

Actinium gave the name to the actinide series, a group of 15 similar elements between actinium and lawrencium in the periodic table.

This transuranic element of the actinide series is located in the periodic table below the lanthanide element europium, and thus by analogy was named after another continent, America.

This led to americium being located right below its twin lanthanide element europium ; it was thus by analogy named after another continent, America: " The name americium ( after the Americas ) and the symbol Am are suggested for the element on the basis of its position as the sixth member of the actinide rare-earth series, analogous to europium, Eu, of the lanthanide series.

The actinide series derives its name from the group 3 element actinium.

Berkelium (, less commonly ), is a transuranic radioactive chemical element with the symbol Bk and atomic number 97, a member of the actinide and transuranium element series.

This element of the actinide series was named after Marie Skłodowska-Curie and her husband Pierre Curie-both were known for their research on radioactivity.

It is a member of the actinide series.

In the periodic table of the elements, it is a period 7 d-block element and the last element of the actinide series.

It was the last element of the actinide series to be produced.

A metallic radioactive transuranic element in the actinide series, mendelevium is usually synthesized by bombarding einsteinium with alpha particles.

A radioactive metal, neptunium is the first transuranic element, and belongs to the actinide series.

The search for element 93 in minerals was encumbered by the fact that the predictions on the chemical properties of element 93 were based on a periodic table which lacked the actinide series, and therefore placed thorium below hafnium, protactinium below tantalum, and uranium below tungsten.

It was the first transuranium element produced synthetically and the first actinide series transuranium element discovered.

In actual practice, the f-block is also included in the form of the lanthanide and actinide series.

Uranium ( ) is a silvery-white metallic chemical element in the actinide series of the periodic table, with symbol U and atomic number 92.

It is a metallic radioactive transuranic element in the actinide series, usually synthesized by bombarding einsteinium with alpha particles.

The first superdeformed states to be observed were the fission isomers, low-spin states of elements in the actinide and lanthanide series.

In 1945, he went against the advice of colleagues and proposed a significant change to Mendeleev's table: the actinide series.

Seaborg's actinide concept of heavy element electronic structure, predicting that the actinides form a transition series analogous to the rare earth series of lanthanide elements, is now well accepted in the scientific community and included in all standard configurations of the periodic table.

The actinide series are the second row of the f-block ( 5f series ) and comprise the elements from Actinium to Lawrencium.

Seaborg's subsequent elaborations of the actinide concept theorized a series of superheavy elements in a transactinide series comprising elements 104 through 121 and a superactinide series inclusive of elements 122 through 153.

In the periodic table, it is located to the right of the actinide curium, to the left of the actinide californium and below the lanthanide terbium with which it shares many similarities in physical and chemical properties.

All but one of the actinides are f-block elements, corresponding to the filling of the 5f electron shell ; lawrencium, a d-block element, is also generally considered an actinide.

It is an actinide element, the sixth transuranium element to be synthesized, and has the second-highest atomic mass of all the elements that have been produced in amounts large enough to see with the unaided eye ( after einsteinium ).

Carbides of the actinide elements, which have stoichiometry MC < sub > 2 </ sub > and M < sub > 2 </ sub > C < sub > 3 </ sub >, are also described as salt-like derivatives of C < sub > 2 </ sub >< sup > 2 –</ sup >.

Other isotopes are synthesized in various laboratories, but at much smaller amounts, by bombarding heavy actinide elements with light ions.

Researchers have shown that mendelevium has a moderately stable dipositive ( II ) oxidation state in addition to the more characteristic ( for actinide elements ) tripositive ( III ) oxidation state, the latter being the more dominantly exhibited state in an aqueous solution ( chromatography being the process used ).

Among the heavy actinide elements, however, those isotopes that have an odd number of neutrons ( such as U-235 with 143 neutrons ) bind an extra neutron with an additional 1 to 2 MeV of energy over an isotope of the same element with an even number of neutrons ( such as U-238 with 146 neutrons ).

* Minor actinides ( MA ), the actinide elements in used nuclear fuel other than uranium and plutonium

Extended to a lattice of magnetic impurities, the Kondo effect likely explains the formation of heavy fermions and Kondo insulators in intermetallic compounds, especially those involving rare earth elements like cerium, praseodymium, and ytterbium, and actinide elements like uranium.

The known elements most susceptible to spontaneous fission are the synthetic high-atomic-number actinide elements with odd atomic numbers: mendelevium and lawrencium, and also some of the transactinide very-heavy elements, such as rutherfordium.

Examples are elements found in the lanthanide and actinide series.

Transactinide elements are also transuranic elements, that is, have an atomic number greater than that of uranium ( 92 ), an actinide.

Curium is a hard, dense, silvery metal with a relatively high melting point and boiling point for an actinide.

Californium is a silvery white actinide metal with a melting point of 900 ± 30 ° C and an estimated boiling point of 1745 ° C.

Depending on what a nuclear reactor is fueled with, the actinide composition in the SNF will be different.

The three naturally-occurring actinide alpha decay chains given below — thorium, uranium / radium ( from U-238 ), and actinium ( from U-235 )— each ends with its own specific lead isotope ( Pb-208, Pb-206, and Pb-207 respectively ).

* The fast breeder reactor's fast neutrons can fission actinide nucleii with even numbers of both protons and neutrons.

The rare earth oxides ( cerium ) and actinide ( thorium ) in the mantle have a low emissivity in the infrared ( in comparison with an ideal black body ), but have high emissivity in the visible spectrum.

; Beamline 4 North ( BL4N ): ( expected completion 2017 ), will be a new 500 MeV beamline used for the proposed expansion of ISAC with a specialized actinide target.

Single fluid fluoride molten salt reactors feature fissile, fertile and actinide radioisotopes in molecular bonds with the fluoride coolant.

It is normal to extract both the uranium and plutonium from the majority of the fission products, but it is not possible to get an acceptable separation of the fission products from the actinide products with a single extraction cycle.