Sagot :
Chlorine is an element with the atomic numer of 17 (I memorize 101/118 elements of the periodic table) and it is a pale green gas. It is mostly used to clean pools. It is a strong chemical (toxic) and it is an irritant.
Chlorine is an element consisting of chlorine atoms. People use chlorine to clean the floors and stuff. It is useful because it makes our surroundings clean especially the water. And also used to combine that specific atom into other kinds of elements to form new kinds of products. Hope this helps =)