Why is chlorine more reactive than iodine? (3 marks)

3 marks so 3 points = chlorine's outer electrons are closer to the nucleus than iodine's (because chlorine has fewer shells)//so chlorine's nucleus is more attracted to its outer electrons than iodine's nucleus is to its outer electrons (positively charged nucleus and negatively charged electrons)//hence chlorine gains an electron more easily than iodine does (because of the attraction)