katodow

Katodow, the Polish term for cathodes, designates electrodes involved in reduction reactions or electron emission in various devices. In electrochemical cells the cathode is the site where reduction occurs. In galvanic (voltaic) cells the cathode is positive; in electrolytic cells it is negative, driven by an external power source. The cathode attracts cations from the electrolyte, which gain electrons and are reduced to neutral atoms or molecules.

In vacuum electronics and electron-beam devices, a cathode is the source of electrons. These electrons are emitted by thermionic, photoelectric, or field emission. Common cathodes include heated tungsten filaments, oxide-coated tungsten, and other materials optimized for longevity and emission in electron guns, cathode-ray tubes, and similar devices.

In corrosion science, the cathode is the part of a metal that undergoes reduction during the overall corrosion process; the anodic region undergoes oxidation and dissolves. In electroplating and electrolysis, metal ions are reduced at the cathode, and a metal layer is deposited on the workpiece.

Typical cathode materials vary by application. Conductive metals such as copper or nickel are used in electrochemical cells, while carbon-based or noble-metal compounds are common in specialized electrodes. Material choice affects conductivity, stability, and emission characteristics. The term katodow appears in Polish-language texts as the plural form of katoda.