A nail is hard. A cotton ball is soft. Why are some objects hard and others soft? Find out in this series about materials and their properties. Informative, at-level text and engaging photographs help... This description may be from another edition of this product.
ThriftBooks sells millions of used books at the lowest everyday prices. We personally assess every book's quality and offer rare, out-of-print treasures. We deliver the joy of reading in recyclable packaging with free standard shipping on US orders over $15. ThriftBooks.com. Read more. Spend less.