Search SEDIS
| Data sets | Publications | Expeditions | Thesaurus |
halogens  | |
|---|---|
| NT | astatine |
| bromine | |
| chlorine | |
| fluorine | |
| iodine | |
| RT | chemical elements |
| SN | Term reintroduced in 1982. Not a valid term from 1972-1981. Five chemical elements from group VIIA in the periodic table. |