Chlorine was first discovered by Karl Scheele (a sweedish chemist) in 1774 ,It was discovered in a compound form of rock salt and then in 1810 it was found out that it was an Element.

It is obtained by oxidation of Hydrogen Chloride with an oxidising agent which removes the Hydrogen to make water and leaves chlorine gas.

When chlorine is a dry formula it reacts with hardly anything but when it is damp it reacts with nearly every element and compound.

Number of protons=17

Atomic mass=35.45

Number of neutrons=18

Number of Electrons=17

M.P= -101.03^oC

B. P= 33.9^oC