1. 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.

2. 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.

3. Unit Nuclear Reactions: not just for everyone

4. Fusion combines small nuclei into larger nuclei, no electrons are involved. Enormous amounts of heat and light are released.

5. 22.1 Nuclear Reactions Nuclear fission the splitting the nucleus of a heavy atom into two or more lighter atoms (fission products). Fission releases a tremendous amount of energy along with two or more neutrons during every split.

7. Large unstable atoms like uranium-238 can become more stable by emitting radiation. It happen regularly in large atoms, and in atoms that have undergone fission. This is called radioactive decay. This radiation can be emitted in several forms. Alpha particles: 2 P+ and 2 N bound together like helium atom (positive). Beta particles: negative particles are 1 e-; positive particles are 1positron (antimatter) X-Rays: very high energy photons of “light” rays beyond what our eyes can see. Gamma rays: incredibly high energy… energy, no particles no mass.

8. Atomic Retirement Community

9. 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.

10. Comparing Chemical and Nuclear Reactions

11. 22.1 Radioactivity An unstable nucleus is radioactive. Unstable isotopes emit three kinds of radioactive decay: — alpha particles — beta particles — gamma rays

13. Using Nuclear Reactions

14. 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.

15. 22.1 Nuclear Reactions Key Question: How do you simulate nuclear decay? *Read text section 22.1 BEFORE Investigation 22.1

16. 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.

17. 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.

18. Incomplete combustion produces harmful by- products.

19. 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.

22. 22.2 Carbon Reactions in the Environment Key Question: How do your choices impact the environment? *Read text section 22.2 BEFORE Investigation 22.2