"Halògens." . . "Halogens." . "Fluorine." . . . . . . . "Fluorine and the halogens" . . "Juvenile works" . . . . . . . "Explains why fluorine and the halogens are good at formimg salts and other substances, and how their compounds affect our food and water, our health, and the natural world." . . . . . "Fluorine : and the Halogens -the periodic table"@en . . "Elements and atomic structure - The periodic table, fluorine and the halogens - Trends in Group 7 [i.e. Group 17] - Fluorine - Chlorine - Bromine - Iodine - Astatine - Timeline." . . . . . "Fluor." . . "Elements químics." . . . . "Flourine." . . "Chemistry." . .