Table of Contents

1. Table of Contents • Polymers and Composites • Metals and Alloys • Ceramics and Glass • Radioactive Elements

2. - Polymers and Composites Carbon Chains and Rings • Carbon atoms can form structures like those shown to the left. In these drawings, lines represent covalent bonds.

3. - Polymers and Composites Forming Polymers • Polymers form when chemical bonds link large numbers of monomers in a repeating pattern.

4. - Polymers and Composites Polymers and Composites • The properties of synthetic polymers make them ideal starting materials for many common objects.

5. - Polymers and Composites Asking Questions • Before you read, preview the red headings. In a graphic organizer like the one below, ask a how or why question for each heading. As you read, write answers to your questions. Questions Answers How do polymers form? Polymers form when chemical bonds link large numbers of monomers in a repeating pattern. How do polymers and composites compare? A composite often includes one or more polymers. Why are there too many polymers? It is often cheaper to throw some polymers away and make new ones than it is to reuse them, resulting in more trash.

6. - Polymers and Composites More on Polymers • Click the PHSchool.com button for an activityabout polymers.

7. End of Section:Polymers and Composites

8. - Metals and Alloys Metals and Alloys • Gold is often alloyed with other metals, such as silver, to improve its hardness and durability. The mass percent of gold in such an alloy is usually expressed by its karat value. Gold karat values and mass percent data are plotted on the graph shown here.

9. The y-axis Reading Graphs: Which axis has values that describe the mass of gold relative to the mass of the alloy? - Metals and Alloys Metals and Alloys

10. The mass percent of gold increases. Reading Graphs: How does the mass percent of gold change as the karat value increases? - Metals and Alloys Metals and Alloys

11. About 58% Interpreting Data: What is the mass percent of gold for a 14-karat gold alloy? - Metals and Alloys Metals and Alloys

12. Creating Data Tables: Create a data table that gives the approximate mass percent of gold for alloys with karat values of 10, 12, 14, 16, 18, 20, 22, and 24. - Metals and Alloys Metals and Alloys

13. - Metals and Alloys Making and Using Alloys • Many alloys are made by melting metals and mixing them together in carefully measured amounts.

14. - Metals and Alloys Outlining Metals and Alloys • As you read, make an outline about metals and alloys that you can use for review. Use the red headings for the main topics and the blue headings for the subtopics. • Comparing Metals and Alloys • Properties of Metals • Properties of Alloys • Making and Using Alloys • Steels • Other Alloys

15. - Metals and Alloys Links on Alloys • Click the SciLinks button for links on alloys.

16. End of Section:Metals and Alloys

17. - Ceramics and Glass Identifying Main Ideas • As you read about ceramics, write the main idea in a graphic organizer like the one below. Then write three supporting details that give examples of the main idea. Main Idea Ceramics are useful because they resist moisture. Detail Detail Detail Many ceramics have a glassy, waterproof coating called a glaze. Ceramic pottery has been used to store food. Ceramics are used as roofing tiles.

18. - Ceramics and Glass Links on Glass • Click the SciLinks button for links on glass.

19. End of Section:Ceramics and Glass

20. - Radioactive Elements Types of Radioactive Decay • During alpha decay, a nucleus loses an alpha particle, which consists of two protons and two neutrons.

21. - Radioactive Elements Types of Radioactive Decay • During beta decay, a neutron inside an unstable nucleus changes into a beta particle and a proton.

22. - Radioactive Elements Types of Radioactive Decay • Gamma radiation has no charge and does not cause a change in either the atomic mass or the atomic number.

23. - Radioactive Elements Types of Radioactive Decay • The three types of nuclear radiation were named based on how easily each one could be blocked. Alpha, beta, and gamma are the first three letters of the Greek alphabet.

24. - Radioactive Elements Radioactive Isotopes • The half-lives of radioactive isotopes range from a fraction of a second to billions of years.

25. - Radioactive Elements Using Radioactive Isotopes • Tracers are radioactive isotopes that can be followed through the steps of a chemical reaction or industrial process.

26. Key Terms: Key Terms: Examples: Examples: alpha particle radioactive dating beta particle gamma radiation tracer half-life - Radioactive Elements Building Vocabulary • A definition states the meaning of a word or phrase by explaining its most important feature or function. After you read the section, reread the paragraphs that contain definitions of Key Terms. Use all the information you have learned to write a definition of each Key Term in your own words. Key Terms: Examples: nuclear reaction Nuclear reactions are reactions involving the particles in the nucleus of an atom. An alpha particle consists of two protons and two neutrons and is positively charged. Scientists can calculate how many half-lives have passed since a plant was alive. In this way, they can estimate the age of the fossil and its surrounding rock. This process is called radioactive dating. A beta particle is a fast-moving electron given off by a nucleus during radioactive decay. radioactive decay In a process called radioactive decay, the atomic nuclei of unstable isotopes release fast-moving particles and energy. Gamma radiation consists of high-energy waves, similar to X-rays. Tracers are radioactive isotopes that can be followed through the steps of a chemical reaction or industrial process. radioactivity Radioactivity is the name that Marie Curie gave to this spontaneous emission of radiation by an unstable atomic nucleus. The half-life of an isotope is the length of time needed for half of the atoms of a sample to decay.

27. End of Section:Radioactive Elements

28. Graphic Organizer Properties of Polymers, Alloys, Ceramics, and Glass Material Made From How Made How Used Chemical bonds link monomers in a repeating pattern Monomers (carbon compounds) Polymers Fabrics Metals and other elements Alloys Metals heated and mixed Tools Ceramics Heated above 1,000ºC Sewer pipes Clay; other materials Sand and limestone and sometimes lead oxide or other materials Melted, then cooled in desired shapes Glass Windows

29. End of Section:Graphic Organizer