Radikali

Radikali is a form used in several languages as the plural of the noun radical (radikal) and also appears as a term across disciplines in a way that centers on the notion of a root or foundational element. In many Slavic languages such as Serbo-Croatian, Bosnian, and Serbian, radikali serves as the ordinary plural for radikal and is used in contexts ranging from science to politics. The underlying idea in these uses is that radicals represent fundamental, root-like elements.

In mathematics, a radical refers to a symbol or concept related to roots. The radical sign (√) denotes the principal square root, and more generally nth roots. A radical expression includes a radicand (the quantity under the root) and a radical sign. Topics include simplifying radical expressions, combining like radicals, and techniques such as rationalizing denominators.

In chemistry, a radical is a species with one or more unpaired electrons, making it highly reactive. Common examples are the hydroxyl radical (·OH) and the methyl radical (·CH3). Radicals play key roles in combustion, polymerization, atmospheric chemistry, and various biological processes. They can be short-lived or relatively persistent depending on stability and surrounding conditions.

In politics and sociology, a radical refers to a person or group advocating fundamental, sweeping changes to a political, social, or economic system. Radical movements aim to alter structures at a foundational level, though the term’s connotations and boundaries vary by historical period and cultural context. It is distinct from extremism in its emphasis on fundamental change, even when methods or goals differ.

Etymology traces radical to Latin radicalis “root,” from radix meaning root. Across languages and disciplines, radikali or radical concepts share the core idea of a root, foundation, or essential element from which other forms or changes emerge.