The four elements called halogens are
Chlorine; Cl. a greenish-yellow gas heavier than air, corrosive,
very poisonous and choking.
Bromine; Br. A dark brown very heavy liquid gives off choking
brown fumes extremely corrosive and poisonous.
Iodine; I. Very dark brown crystals, gives off purple vapour on
gentle heating. Corrosive and poisonous.
Astertine Very rare, strongly radioactive. only available in
very specialized laboratories Thus the halogens form a special group
in the Atomic Table, and have similar chemical properties. Chlorine
combines with the metal sodium to produce sodium chloride, table
salt. Bromine forms similar salts with sodium metal, making sodium
bromide. Iodine and sodium gives sodium iodide. All the halogens are
highly reactive and combine with hydrogen to form corrosive acids;
examples; Hydrochloric acid, Hydrobromic acid, Hydriodic acid. And
of course, combine with many other basic chemicals producing salts.
A salt is produced by the combination of an acid with an alkali or
And I think that is enough chemistry for now. But further questions
are quite welcome.
Cheers for now,
JohnB of Mapua, Nelson NZ