actinide

(noun)

Any of the 14 radioactive elements of the periodic table that are positioned under the lanthanides, with which they share similar chemistry.

Related Terms

  • lanthanide contraction
  • transuranium
  • lanthanide

Examples of actinide in the following topics:

  • Lanthanides and Actinides

    • Lanthanides and actinides are elements of the inner transition series of the periodic table.
    • Actinides are typical metals.
    • Like the lanthanides, all actinides are highly reactive with halogens and chalcogens; however, the actinides react more easily.
    • Actinides, especially those with a small number of 5f electrons, are prone to hybridization.
    • Most actinides exhibit a larger variety of valence states.
  • The Bottom of the Periodic Table

    • By expanding the horizontal dimensions of the table, the actinide and lanthanide rows can be put into their correct relative positions.
    • Taking the extension of the periodic table even further, consider an element with atomic number 92 in the actinide series, called uranium.
    • In 1934 only 4 actinides were known, all smaller than uranium, so it was not known that they formed a period or family like the lanthanides.
    • The actinides were added along with the lanthanides.
    • The lanthanides and actinides are added as separate but connected rows, building what is called the f-block.
  • The Periodic Table of Elements

    • Although groups generally have more significant periodic trends, there are regions where horizontal trends are more significant than vertical group trends, such as in the f-block, where the lanthanides and actinides form two substantial horizontal series of elements.
  • Carbides

    • Carbides of the actinide elements, which have the structure MC2 and M2C3, are also described as salt-like derivatives of C22-.
  • General Trends in Chemical Properties

    • The f block, usually offset below the rest of the periodic table, includes the lanthanides and actinides.
  • Coordination Number, Ligands, and Geometries

    • Due to their large size, lanthanides, actinides, and early transition metals tend to have high coordination numbers.
Subjects
  • Accounting
  • Algebra
  • Art History
  • Biology
  • Business
  • Calculus
  • Chemistry
  • Communications
  • Economics
  • Finance
  • Management
  • Marketing
  • Microbiology
  • Physics
  • Physiology
  • Political Science
  • Psychology
  • Sociology
  • Statistics
  • U.S. History
  • World History
  • Writing

Except where noted, content and user contributions on this site are licensed under CC BY-SA 4.0 with attribution required.