Chapter 22.1 Notes I. Nuclear Reactions A. Nuclear reactions involve either combining or splitting the nuclei of atoms. B. Two kinds of nuclear reactions…. 1. Fusion- the process of combining nuclei of atoms to make different atoms. 2. Fission- breaking up the nucleus of an atom.

a. protons and neutrons participate in nuclear reactions. b. You need to know that the protons and the neutrons in the nucleus are referred to as nucleons. II. Chemical vs. nuclear reactions * There are some similarities and some differences between the two….let’s look at some…..

Chemical reactions Nuclear reactions What part of the atom is involved? Outermost electronsProtons and neutrons in the nucleus How is the reaction started? Atoms are brought close together by high temperature or pressure, or catalysts High temperature is required or atoms are bombarded with high- speed particles What is the outcome of the reaction? Atoms form ionic or covalent bonds The number of protons and neutrons in an atom usually changes How much energy is absorbed or released? A small amountA huge amount What are some examples? Burning fossil fuels, digesting food, housecleaning, making medicines Nuclear energy, taking x-rays, treating cancer, sun generating heat and light

III. Forces in the nucleus A. Why are nuclear reactions so powerful? 1. For review, like charges ______ and opposite charges _______.... * if this is true, why don’t the protons in the nucleus not push each other apart? 2. There is a strong nuclear force what attracts every proton and neutron to every other proton and neutron.

a. Neutrons are essential because they add strength to the nuclear force without adding any charge. b.For atoms with more than 83 protons, the nuclear force cannot hold the nucleus together…. c. Therefore, every element with more than 83 protons is considered to be unstable.

IV. What is radioactivity? A. Radioactivity is how we describe any process where the nucleus emits particles or energy. B. There are three types of radiation that may be emitted by an unstable isotope. 1. Alpha particles 2. Beta particles 3. Gamma rays

Ch Notes I. Nuclear Wastes and Nuclear Reactors A. Storing Nuclear Waste 1. In 1974, the U.S. Congress established the Nuclear Regulatory Commission (NRC) as a monitoring organization for nuclear fuel use and the storage of nuclear waste. 2. There is a proposed plan to store nuclear wastes in a nuclear facility in Yucca Mountain, Nevada-to be built by ( Do you see what could be a problem with this?) I

B. The United States gets about 15% of its energy from nuclear fission reactors. 1. The remaining energy comes from coal, natural gas, oil and hydroelectric dams. a. Just FYI- France is the most dependent upon nuclear power. i. About 75% of electricity generated comes from nuclear fission. Ii. Sweden and Belgium get more than 50% of their energy from nuclear power plants. C. Why use nuclear fusion instead of nuclear fission?

1. Fusion is very difficult to occur. a. We would have to generate about 100 million degrees Celsius to create fusion. b. If we could ever achieve this, it would be beneficial because fusion does not produce any waste. D. Using radioactivity in medicine 1. Radioactive isotopes are often used in medicine and they are called tracers.

2. These isotopes are counted using machines such as the Geiger counter. E. Marie Curie 1. She was a polish born chemist who worked mainly with her husband, Pierre Curie to discover radioactivity. 2. They were awarded the Nobel Prize in 1903 for her discovery of radioactivity and another Nobel Prize in 1911 for discovering radium and polonium. 3. She was the first woman to graduate from her college with a degree in physics. 4. She was also the first woman to win a Nobel Prize. 5. In addition, she is credited with linking radiation therapy to being a treatment for cancer.