Chlorine is the most important element of a family of very reactive non_metals known as the halogens.the halogens are found in group 7 of the periodic table.
Chlorine was first discovered by Scheele in 1774 when he heated some concentrated by hydrochloric acid with manganese(iv)oxide.in 1810,Davy named the gas chlorine,a derivative of the greek word chloros,meaning greenish_yellow.
It doesnt occur free in nature because it is too reactive.instead is usually found in combined state as chlorides.
Physical properties are:
#1. Chlorine is greenish-yellow gas with an unpleasant choking smell.
#2. It is about 2.5 times denser than air
#3. It is poisonous
#4. It can easily be liquefied under a pressure of about 6 atmospheres.
Chemical properties are:
Chlorine atom has seven valence electrons.it is very reactive as it tries to achieve stable electron octet either.
Tests for chlorine
Chlorine can be tested by:
#1. Damp litmus paper test
#2. Starch iodide paper test