Page 182 - The Periodic Table Book

17
Cl Chlorine

Discovery: 1774
17 17 18 State: Gas
The Halogen Group This orange colour is contains a chlorine compound. Red-eyed tree frog
Forms

due to the presence of
The skin of this tree frog
the mineral hematite.

This glass sphere
Halite
traps pure chlorine
so as to prevent any
reactions with air. a glass sphere

Pure chlorine in

Cube-shaped crystals
Carnallite

Pure
The intense red chlorine
colour is due is heavier
to impurities. than air.

Chlorine is named after the Greek word chloride, found in nature as the mineral halite.
chlóros, which means “pale green”, a reference Chlorine compounds are important for the body
to the colour of this gaseous element. Chlorine and are used by muscles and nerves. They are also
is a highly reactive gas that forms a number of present in sweat. As it is poisonous in its pure form,
compounds, and does not exist pure in nature. chlorine gas was used as a weapon during World
180 The most common chlorine compound is sodium War I: soldiers had to wear masks for protection

180-181_Chlorine.indd 180 02/12/16 6:54 pm