(Original post by rakib567)
b and c
i cut out the other easy bits of the question
B) basically, the number of different atoms that form the compound. Each one will produce a peak. Be careful with the chlorine though, account for the fact there's two isotopes.
The m/z value is the sum of the molecular masses of the constituent elements in the compound. Again be careful as to what value you use for chlorine
C) apparently this is a so called "A* question". Essentially you need high temperatures to maximise waste destruction in incinerators, which thus prevents the dioxins from forming