English Reference

Word

halogen

Phoneticshalo·gen

US/ˈhæɫədʒən/

UK/hˈælədʒən/

Definition

n. a group of chemical elements that are very reactive and often used in things like light bulbs and cleaning products. They include elements like fluorine, chlorine, and iodine.

n. any of the elements in group 17 of the periodic table, characterized by high reactivity and the tendency to form salts. Includes fluorine, chlorine, bromine, iodine, and astatine.

Examples

“Chlorine is a common halogen used for disinfecting water.”

“The chemist explained that halogens are highly reactive and must be handled with care in the laboratory.”

“The unique electronic configuration of halogens allows them to readily accept an additional electron, making them powerful oxidizing agents in various industrial applications.”

Examples

simple

“Chlorine is a common halogen used for disinfecting water.”

contextual

“The chemist explained that halogens are highly reactive and must be handled with care in the laboratory.”

complex

“The unique electronic configuration of halogens allows them to readily accept an additional electron, making them powerful oxidizing agents in various industrial applications.”

Real-World Examples

“Older halogen setups, particularly the reflector housings common through the 1980s, 1990s, and early 2000s, produced a comparatively soft, warm beam with limited reach.”
Ars Technica · 3 Aug 2026
“This is sometimes done with butane or alcohol heaters, and sometimes with heat from an adjustable halogen bulb, as is the case with these Yama Brewers .”
Sprudge · 27 Apr 2014

Etymology

From Ancient Greek ἅλς (háls, “salt" or "sea”) + γεν- (gen-), "to produce" (coined by Berzelius in 1842). By surface analysis, halo- (“salt”) + -gen (“forming”).

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

Domain

Chemistry

This entry

Level
C1 · Advanced
Frequency
Occasional
Updated

Scan code

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English Reference