Halogen
/ˈhælədʒən/noun
Any of the reactive non-metals fluorine, chlorine, bromine, iodine and astatine, which form salts with metals.
The Greek roots
Literally: “salt-producer”
The story of the word
Johann Schweigger proposed the name around 1811 for the gas Humphry Davy had just called chlorine, arguing that what mattered about it was that it made salt out of metals. Davy's colour-based name won, and halogen was recycled a couple of decades later by Berzelius as the label for the whole family. Domestic halogen lamps take the name from the trace of iodine or bromine inside the bulb, which carries evaporated tungsten back onto the filament instead of letting it blacken the glass.
- How it travelled
- Ancient Greek → scientific coinage → English
- First recorded
- 19th century
Same family
In a sentence
Fluorine is the most aggressive halogen and will attack glass.
We swapped the halogen floodlight for LEDs and the electricity bill dropped.