Books
Elements, Compounds, and Mixtures (Let's Wonder About Science)

Color photos and simple text make this a good introduction to elements and compounds for 2nd-3rd grades.
Elements and Compounds (Why Chemistry Matters)

Written by a former classroom teacher, this book for upper-elementary students focuses on the chemical compounds that make up all kinds of objects in the world around us. Includes a fun "disappearing eggshell" experiment that illustrates chemical bonds.
Chemistry (DK Eyewitness Books)

DK Eyewitness books are favorites of kids everywhere for their fascinating facts and images. This volume provides an engaging, visually intriguing overview of chemistry, including a chapter on "Investigating Compounds." Included are lots of fun details, colorful pictures, clear information, and historical timelines.
Fizz, Bubble & Flash: Element Explorations and Atom Adventures for Hands-On Science Fun!

Unlike many books of chemistry experiments, this one focuses on the atomic science of elements and compounds. Using common items, kids can observe carbon dioxide in action, separate the iron out of breakfast cereal, dissolve calcium sulfate into calcium ions, and more. Clear explanations and an engaging exploration of the periodic table.
Molecules: The Elements and the Architecture of Everything

Stunning photographs illustrate the ways atoms combine to form molecules and compounds. The author explores the variety of useful materials that chemical compounds can create through interesting stories and graphics. Science-minded younger kids will be attracted to the beautiful pictures, while the engaging text will interest older kids and adults. This is a big, lavish book that can be enjoyed in small doses by curious minds of all ages.
Why are Chemicals Not Named Joe? Naming Chemical Compounds

Who came up with chemical names? Naming chemical compounds is the work of the chemists who discovered them and the universal rules for naming molecules. An interesting overview aimed at 6th graders.
Elements and Compounds (Chemicals in Action)

Part of the Chemicals in Action series, this book includes experiments, demonstrations, and easily-understood explanations of key terms and concepts.