Chapter 15 The p-block elements (III) x§15.1 The halogens x*§15.2 The rare gases x 15.3 The property variations for compounds of p-block elementsChapter 15 The p-block elements ( Ⅲ ) §15.3 The property variations for compounds of p-block elements * §15.2 The rare gases §15.1 The halogens