The Quran's 114 chapters (or surahs) are not arranged topically or chronologically, but rather in descending order (more or less) by length, with the exception of the first, short, introductory surah. The chronological order of the surahs is important in Islam, however, since later surahs are given more weight than earlier ones, due to the doctrine of abrogation. The list below is the traditional chronological ordering of the surahs in the Quran, though very little is known about the correct chronological order. Here is a short video that discusses this.