# anode

> electrode through which conventional current flows into a polarized electrical device

**Wikidata**: [Q181232](https://www.wikidata.org/wiki/Q181232)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Anode)  
**Source**: https://4ort.xyz/entity/anode

## Summary
An anode is an electrode through which conventional current flows into a polarized electrical device. It is a subclass of electrode and functions as the opposite of a cathode, representing the role where current enters a device. The term was named by William Whewell and is fundamental to the operation of various electrical and electrochemical systems.

## Key Facts
- **Definition**: An electrode through which conventional current flows into a polarized electrical device.
- **Classification**: Subclass of electrode; instance of a role regarding electric current.
- **Opposite**: Cathode.
- **Named by**: William Whewell.
- **IEC Number**: 482-02-27.
- **IUPAC Gold Book ID**: A00370.
- **Dewey Decimal Classification**: 660.29724 and 541.3724.
- **Library of Congress ID**: sh85005376.
- **Sitelink Count**: 68.
- **Image**: https://commons.wikimedia.org/wiki/Special:FilePath/Zinc_anode_2.svg
- **Part of**: Vacuum tube, gas-filled tube, diode, light-emitting diode, silicon controlled rectifier, thyristor, battery.
- **Contains/Subsidiaries**: Galvanic cell (inception: 1786), triode, voltage regulator tube, nonode, thyristor.
- **Aliases**: polo positivo, Antikathode, 陽極, 氧化极, Anode, 阳极, anodo, أنود, الأنود, الآنود, 양전극.
- **Treccani Author**: Enrico Fermi (1929).
- **Museum Cataloging**: Nomenclature for Museum Cataloging ID 8795.

## FAQs
**What is the primary function of an anode?**
The anode serves as the electrode through which conventional current flows into a polarized electrical device, acting as the entry point for current within the system.

**What types of devices utilize an anode?**
Anodes are integral components of vacuum tubes, gas-filled tubes, diodes, light-emitting diodes, silicon controlled rectifiers, thyristors, and batteries.

**Who is credited with naming the anode?**
The term "anode" was named by William Whewell.

**How does an anode relate to other electrical components?**
It is a subclass of electrode and is the opposite of a cathode; it is also part of complex devices like the nonode (a vacuum tube with nine electrodes) and the galvanic cell.

**What are some authoritative references for the term anode?**
The term is defined by the IEC (482-02-27) and the IUPAC Gold Book (A00370), and it has been documented in Meyers Konversations-Lexikon (4th edition) and the Armenian Soviet Encyclopedia (vol. 1, p. 430).

## Why It Matters
The anode is a foundational concept in electrical engineering and electrochemistry, defining the direction of current flow and energy conversion in polarized devices. Its distinction from the cathode is critical for the design and analysis of circuits, batteries, and semiconductor devices. By serving as the terminal where current enters, the anode facilitates the operation of energy storage systems like batteries and electronic components like diodes and vacuum tubes. The concept's standardization across various international bodies (IEC, IUPAC) ensures consistent communication and understanding in scientific and industrial applications.

## Notable For
- Being the specific electrode type through which conventional current enters a polarized electrical device.
- Its role in the galvanic cell, a device dating back to 1786 used for the spontaneous conversion of chemical energy into electrical energy.
- Inclusion in the nonode, a specialized vacuum tube containing nine electrodes.
- Documentation by notable physicist Enrico Fermi in Treccani's Enciclopedia Italiana in 1929.
- Possessing a wide array of multilingual aliases, including polo positivo, Antikathode, 陽極, and anodo.

## Body

### Classification and Definition
The anode is defined as an electrode through which conventional current flows into a polarized electrical device. It is classified as a subclass of electrode, which is an electrical conductor used to make contact with a nonmetallic part of a circuit. As an instance of a role specifically related to electric current, the anode is the direct opposite of the cathode. The entity is identified by numerous multilingual aliases, such as polo positivo, Antikathode, 陽極, 氧化极, Anode, 阳极, anodo, أنود, الأنود, الآنود, and 양전극.

### Components and Devices
The anode is a critical component in a wide array of electrical and electronic devices. It is part of vacuum tubes, gas-filled tubes, diodes, light-emitting diodes, silicon controlled rectifiers, thyristors, and batteries. Within the hierarchy of electrodes, it is related to the Plate electrode (a type of electrode used in vacuum tubes) and the galvanic anode (the main component of cathodic protection).

Conversely, the entity "anode" is associated with containing or being a parent to several specific devices and configurations:
- **Galvanic Cell**: A device for the spontaneous conversion of chemical into electrical energy, with an inception date of 1786.
- **Triode**: A single-grid amplifying vacuum tube having three active electrodes.
- **Voltage Regulator Tube**: A gas-filled tube for voltage regulation employing either glow or corona discharge.
- **Nonode**: A specialized vacuum tube having nine electrodes – cathode, anode, and seven grids.
- **Thyristor**: A semiconductor device with three p-n junctions, having two steady states (off and on) and three terminals.

### Historical Context and Nomenclature
The term "anode" was named by William Whewell. Historical documentation of the concept appears in Meyers Konversations-Lexikon (4th edition, 1885–1890) and the Armenian Soviet Encyclopedia (vol. 1, p. 430). A significant entry in Treccani's Enciclopedia Italiana (ID: anodo) was authored by Enrico Fermi in 1929. The concept is also covered in Treccani's Dizionario delle scienze fisiche (1996).

### Standardization and Identification
The anode is subject to rigorous standardization and cataloging across various international systems:
- **IEC**: IEV number 482-02-27.
- **IUPAC**: Gold Book ID A00370.
- **Library of Congress**: sh85005376.
- **Dewey Decimal**: 660.29724 and 541.3724.
- **Nomenclature for Museum Cataloging**: 8795.
- **BNF Thesaurus**: 39931.
- **Great Russian Encyclopedia Portal**: anod-4d9126.
- **Australian Educational Vocabulary**: scot/1344.

### Digital and Academic Presence
The anode has a significant digital footprint, with a Wikipedia sitelink count of 68 and coverage in numerous languages including Arabic, German, English, French, Japanese, and Chinese. It is categorized under the Commons category "Anodes." Academic and scientific databases index the concept under various IDs:
- **GND ID**: 4142547-9.
- **BabelNet ID**: 00004388n.
- **Freebase ID**: /m/0z2f.
- **ScienceDirect Topic ID**: materials-science/anode.
- **WordNet 3.1 Synset ID**: 02717226-n.
- **Open Library Subject ID**: anodes.
- **JSTOR Topic ID (Archived)**: anodes.
- **Omegawiki Defined Meaning**: 717429.
- **Yale Lux ID**: concept/5d52b0e8-c5c6-4e84-893c-f67789095d41.
- **World of Physics ID**: Anode.
- **Microsoft Academic ID (Discontinued)**: 89395315.

The entity is also referenced in commercial contexts such as the Google Play Store ID (anode) and Quora topics.

## References

1. Freebase Data Dumps. 2013
2. Integrated Authority File
3. BabelNet
4. Quora
5. National Library of Israel Names and Subjects Authority File
6. GF WordNet
7. [OpenAlex](https://docs.openalex.org/download-snapshot/snapshot-data-format)