G’day. As soon as I had sent the previous message on the halogens I
suddenly realised I had left out Fluorine, (put it down to a Senior
Moment) so here’s a remake:
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.
Fluorine; F colourless, very corrosive and reactive gas, very
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. Fluorine
and sodium gives sodium fluoride.
All the halogens are highly reactive and combine with hydrogen to
form corrosive acids; examples; Hydrochloric acid, Hydrobromic
acid, Hydriodic, acid Hydrofluoric acid - the one which dissolves
glass and quartz. 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 base.
And I think that is enough chemistry for now. But further
questions are quite welcome.
Cheers for now,
JohnB of Mapua, Nelson NZ