Lanthanides, also known as the lanthanoid series or rare earth elements, refer to a group of 15 metallic chemical elements located in the periodic table. These elements include lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu). These elements possess similar characteristics, including their shiny appearance, high electrical conductivity, and ability to form stable ions, tending to have +3 oxidation state.
Lanthanides are categorized as rare earth elements due to their scarcity in the Earth's crust, although they are not inherently rare. They were initially named "lanthanides" based on the first element in the series, lanthanum. These elements have numerous applications in modern technology, including electronics, magnets, catalysts, and phosphors for lighting.
Lanthanides have unique chemical properties, such as the presence of f-orbitals in their atomic structure, which give rise to their distinctive electronic properties. Their electrons are shielded by the outer 5s and 5p orbitals, giving them similar chemical behavior. These elements also possess similar atomic radii, melting points, and high densities.
In summary, lanthanides constitute a group of metallic chemical elements residing in the periodic table, consisting of 15 rare earth elements. They share similar physical and chemical properties, and their applications span across various technological fields.
