Evolutionary biologist Richard Dawkins attempts in this book to address some of the questions that might arise in the minds of children about topics with which science deals. It was written for kids of unspecified age; I would guess that middle school would be a reasonable estimate.
I enjoyed so much Dava Sobel's previous books, "Longitude" and "Galileo's Daughter" (both of which were Hal's Picks), that I was eager to read her latest, which was judged "best science book" for Fall, 2011 by Publisher's Weekly.
Poisons are among the favorite weapons of mystery writers, if not murderers. Guns may be quicker, but poisons have a cachet that you really can't beat. On the other hand, murder by poison has become increasingly dangerous - to the perpetrator!