radicalen

Radicalen is the Dutch plural form of radical and is used in several domains to describe distinct but related ideas. In chemistry, radicalen are free radicals: atoms or molecules that contain one or more unpaired electrons, making them highly reactive. They are key intermediates in combustion, polymerization, and atmospheric chemistry. Common examples include the hydroxyl radical OH•, hydrogen radical H•, and methyl radical CH3•.

Free radicals are formed by homolytic bond cleavage, photolysis, radiolysis, or redox processes, and their reactions often proceed through chain mechanisms. Their reactivity is influenced by electron delocalization (resonance) and by steric effects. They are detected by electron spin resonance (ESR) spectroscopy and can be stabilized temporarily by reactive traps such as nitroxide spin traps.

In mathematics, the term radical denotes expressions involving roots, typically shown with the radical symbol √. It covers square roots, cube roots, and nth roots. The mathematics of radicals includes simplification, rationalization, and operations on sums and products of radical expressions. The concept is fundamental to solving equations and to areas such as algebra, geometry, and numerical methods.