把蠟筆放進火堆裡會否助燃呢？

yes, but you say some wrong things. 蠟筆和蠟燭不是用同一種物質做的, although they are both alkane(烷烴) ,but they have different numbers of carbon, so 蠟筆 is hard then 蠟燭, and 蠟筆本身是一種燃料, they can be burned with themself, but not助燃(這時的助燃物is oxygen).

no ,蠟燭中have some things!