Unit 7, Chapter 22

1. Unit 7, Chapter 22 Integrated Science

2. Unit Seven: Changes in Matter Chapter 22 Chemistry and the Environment • 22.1 Nuclear Reactions • 22.2 Carbon Reactions and the Environment

3. Chapter 22 Learning Goals • Compare and contrast nuclear reactions with chemical reactions. • Describe the environmental impact of nuclear reactions. • Research and describe the environmental and economic impact of the end-products of chemical reactions. • Identify how personal choices about products can have an impact on the environment. • Evaluate the impact of scientific research on society and the environment. • Organize data and use it to predict trends.

4. half-life neutral nuclear reactions nucleons photosynthesis radiation radioactive radioactive isotope stable unstable Chapter 22 Vocabulary Terms • alpha decay • alpha particles • beta decay • beta particles • carbon dating • emissions • fission • fossil fuels • fusion • global warming

5. 22.1 Nuclear Reactions • In the Middle Ages, individuals called alchemists spent a lot of time trying to make gold. • Making an element is possible only if you can achieve a nuclear reaction. • Nuclear reactions involve either combining or splitting the nuclei of atoms.

6. 22.1 Nuclear Reactions • There are two kinds of nuclear reaction: fusion and fission. • The process of combining the nuclei of atoms to make different atoms is called fusion.

8. 22.1 Nuclear Reactions • Breaking up the nucleus of an atom is called fission.

10. 22.1 Nuclear Reactions • Fission and fusion are nuclear reactions. • Protons and neutrons—the two most important subatomic particles in the nucleus—participate in these reactions. • Collectively, the protons and neutrons in the nucleus are called nucleons.

11. Comparing Chemical and Nuclear Reactions

12. 22.1 Radioactivity • Unstable isotopes emit three kinds of radioactive decay: • alpha particles • beta particles • gamma rays • An unstable nucleus is radioactive.

14. Using Nuclear Reactions

15. 22.1 Using Nuclear Reactions • Radioactive isotopes can be used to detect problems in organ systems. • The age of some fossils can be determined using radioisotopes such as carbon-14. • It is possible to figure out the age of objects made from plants or animals that are between 50,000 and a few thousand years old using carbon dating.

16. Key Question: How do you simulate nuclear decay? 22.1 Nuclear Reactions *Read text section 22.1 BEFORE Investigation 22.1

17. 22.2 Carbon Reactions in the Environment • We all depend on the carbon reactions performed by plants. • Plants convert the sun’s energy into products we use.

18. 22.2 Carbon Reactions in the Environment • We depend on carbon reactions for transportation. • Cars burn fossil fuels for energy. • Use of fossil fuels affects the environment.

19. Incomplete combustionproduces harmful by-products.

20. 22.2 Carbon Reactions in the Environment • Incomplete combustion means more air pollution. • The catalytic converter, introduced in the 1970s, reduces hydrocarbon and carbon monoxide emissions by converting these molecules to carbon dioxide and water.

23. Key Question: How do your choices impact the environment? 22.2 Carbon Reactions in the Environment *Read text section 22.2 BEFORE Investigation 22.2