halogen

Meanings

1. 1nouncountable

   Any of the very reactive nonmetal elements in group 17 of the periodic table, such as fluorine, chlorine, bromine and iodine.

   Grammar: Usually plural when talking about the group: the halogens are reactive.

   Patterns

   • a halogen such as chlorine

   Chlorine is a halogen that is used to disinfect swimming pools.

   Each halogen needs just one more electron to fill its outer shell.

   Students compared how bromine and iodine, both halogens, react with metals.

2. 2nouncountable or uncountable

   A bright light bulb or lamp that contains halogen gas, giving a strong white light.

   Grammar: Often used before another noun: a halogen lamp, a halogen bulb.

   Patterns

   • a halogen bulb

   The garage was lit by a single halogen above the workbench.

   We swapped our old halogen for an LED to save energy.

   The cooker has a halogen element that heats food in minutes.

Word forms

Common combinations

halogen lamp

The halogen lamp on the desk grew hot after an hour.

halogen bulb

A halogen bulb burns brighter than an old filament bulb.

halogen element

Fluorine is the most reactive halogen element.

group of halogens

The group of halogens includes five elements.

halogen headlights

The old car still had halogen headlights.

Synonyms and how they differ

group 17 element

Group 17 element is the formal classification label, while halogen is the common chemistry name for those same elements.

Opposites

Word family

halogenated adjective

containing a halogen atom added to a compound

halogenation noun

a reaction that adds a halogen to a molecule

halide noun

a compound of a halogen with another element

Commonly confused: halogen or halon?

Practice

Make it your own

Write a sentence using “halogen”, then check it and compare it with the examples above.

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