The reading selections (see Table of Contents) on this site are from Properties of Matter, a module in the National Science Resources Center’s (NSRC) Science and Technology Concepts for Middle Schools™ (STC/MS) curriculum. All reading selections contain hyperlinks to related definitions and Web sites. Images may also be hyperlinked.

Most reading selections have a link near their title to a file of English audio synchronized to English and Spanish text. You must have Shockwave player installed on your computer to use this feature. Download Shockwave. When first using this feature, you will also be prompted to download tools for running Synchrotext software; this is a one-time quick and safe download. (See this site's download media players page for more information on installing Shockwave.)

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The NSRC worked with experienced teachers in classroom settings to field test this site.

Because students can access the Web site from home, restrictions on Web site use are the responsibility of parents. All links to non-NSRC Web sites led to appropriate and relevant material when this site was developed. The NSRC is not responsible for changes to these linked sites. Please contact nsrcinfo@si.edu if you think that any linked material is unsuitable or inappropriate for children. Use the “Contact” link in the footer at the bottom of each page if you encounter problems or have questions regarding the site.