Science 30 Unit D - Energy and the Environment Section 8 Alternative Energy Name Table of Contents McKennitt 8.1 Radiation and Nuclear Reactions 8.2 Nuclear Energy 8.3 Alternative Types of Energy Science 30 Energy and The Environment (Unit D) Page 1
Science 30 Energy and The Environment (Unit D) Page 2
Lesson 8.1 Nuclear Energy - Radiation and Nuclear Reactions The Atom Review Nucleons - protons and neutrons The atomic mass is the number of nucleons The atomic number is the number of protons. Isotopes are a particular element with a different number of nucleons. (i.e. carbon-12, carbon-13) Practice: How many protons and neutrons are in the following? Write the following in nuclear notation. Carbon-14 Uranium-235 Silicon-27 Phosphorus All right now lets split some atoms! Science 30 Energy and The Environment (Unit D) Page 3
Radioactive Decay- Unstable nucleus emit radiation particles in both natural and man-made processes. We will look at alpha, beta, and gamma radiation. In addition, we will look at nuclear fission and fusion. (p. 8 of data book) You need to be able to write the formulas for all five and recognize each of them. We will be balancing these reactions to keep the left side equal to the right side for both the nucleons and the atomic number. 1. Alpha Particle Radiation/Decay a positively charged particle with two neutrons and two protons. Practice: Alpha particles emitted during the decay of americium-241 ionize molecules in the air that allow a current to flow in a smoke detector. During a fire, smoke particles that come between these two plates interfere with the current, setting off the detector s alarm. Write a balanced chemical equation showing the decay of americium-241 into an alpha particle and another product. 2. Beta Radiation - a high-speed electron emitted from an unstable nucleus; the result of the change of a neutron to a proton during a nuclear reaction. A stream of beta particles is called beta radiation. Beta decay is when a nucleus ejects a beta particle. Beta particles come from the nucleus when a neutron is converted to a proton. Practice: Write the beta decay of carbon-14. Science 30 Energy and The Environment (Unit D) Page 4
3. Gamma Radiation - Gamma radiation consists of photons with no mass or charge. Gamma radiation is usually accompanied by alpha or beta radiation. Practice: Write a balanced nuclear equation to describe the emission of beta and gamma radiation from a cobalt-60 source. The graphic below shows that alpha radiation is stopped by a sheet of paper, wood stops beta particles, but lead or concrete are required to stop gamma rays. 4. Nuclear Fission A nuclear reaction in which a large nucleus splits into smaller nuclei or particles. It occurs when a large element is struck by neutron and is able to break down into two smaller fission products and three neutrons. There is an extremely high amount of energy released, much more than in a chemical reaction. Science 30 Energy and The Environment (Unit D) Page 5
Example - If uranium-235 undergoes nuclear fission it will produce 3 neutrons, krypton-92, and barium-141. Write the equation below. 5. Nuclear Fusion Two smaller nuclei are joined together (or fused) to form a larger nucleus, with the simultaneous release of energy. Science 30 Energy and The Environment (Unit D) Page 6
8.1 Homework Read ALL OF SECTION 1.4 in the textbook on Nuclear Energy! p.503-517 #26-36 and 40 Science 30 Energy and The Environment (Unit D) Page 7
Science 30 Energy and The Environment (Unit D) Page 8
Lesson 8.2 Nuclear Energy Sustainability Canada and the rest of the world are trying to come up with sustainable sources of energy. Is Nuclear Power the answer? Nuclear Power Nuclear Powers use the principles of we looked at last lesson in a chain reaction. A occurs when one reaction causes one or more nuclear reactions, thus leading to a of these reactions. The specific nuclear reaction may be the fission of heavy isotopes (e.g. 235U). The nuclear chain reaction is unique since it releases several per reaction than any chemical reaction. Nuclear Reactor Products of a fission reaction have large quantities of kinetic energy. A nuclear power plant enables the release of allowing it to be transformed into useful electricity. Nuclear power plants are similar to fossil fuel power plants in that they are both thermal sources of electricity. stands for "Canada Deuterium Uranium". It is a pressurized heavy-water power reactor designed first in the late 1950s by a consortium of Canadian government and private industry. are of the CANDU type. Science 30 Energy and The Environment (Unit D) Page 9
Nuclear Fuel has the key advantages of: Not producing CO2, SO2, and NOx pollutants like fossil fuel plants Allowing for large returns on the reaction compared to the amount of uranium available. However nuclear fuel produces radioactive waste that needs to be stored for hundreds-thousands of years. In addition, there exists a possibility of nuclear terrorism or a meltdown. The Possible Future: Nuclear Fusion Nuclear occurs in stars under incredible temperatures and pressure to fuse together light elements into heavier elements, in the process producing enormous amounts of energy. If we could harness this power in a power plant we could solve our worldwide energy problem. Currently, we are a long way off of this becoming a reality News Article EU Nuclear Fusion Plants and NK Amount of Energy released in different reactions Phase < Chemical < Nuclear Fission < Nuclear Fusion Energy Release in Nuclear Reactions Albert Einstein drew a link between mass and energy in one of the world s most famous equations. (p.514 of text) Now, we can see that any difference between the masses of the products and reactants of a process must be the result of mass having been converted into energy. Remember, this is only the unaccounted for mass or the mass that seems to have disappeared from existence Science 30 Energy and The Environment (Unit D) Page 10
Practice Problems (p.514-515 text) 1. In a fission reaction of 1 mol of beryllium-8 the mass of the products is determined to the 2.29x10-5 kg less than the mass of the reactants. Calculate the change in energy that corresponds with this change in mass. Identify whether this reaction is exothermic or endothermic. 2. Use the Masses of Subatomic Particles and Radiation from the Data Booklet to calculate the change in mass between reactants and products in beta decay. Identify whether the reaction is endothermic or exothermic. 3. The fission of uranium-235 that occurs in a CANDU reactor involves the following reaction: Calculate the change in mass between the reactants and products for this reaction and the corresponding energy change. Science 30 Energy and The Environment (Unit D) Page 11
8.2 Homework p.512 #37-41 and p.519 #1-8 Science 30 Energy and The Environment (Unit D) Page 12
Science 30 Energy and The Environment (Unit D) Page 13
8.3 Alternative Types of Energy Besides Fossil Fuels and Nuclear Energy, there are many alternative types of energy. Renewable Resources Hydroelectric Wind Geothermal Heat Tidal and Wave Solar (Passive) Solar (Active Photovoltaic Cells) Biomass Hydrogen Fuel Non-Renewable Resources Fossil Fuels Nuclear Energy For each of the above types of alternative energies, research how they work, how energy cycles through, and list some advantages and disadvantages for each. You are responsible for knowing ALL OF THE ABOVE alternative types of energy. Renewable energy - comes from resources which are naturally replenished on a human timescale such as sunlight, wind, rain, tides, waves and geothermal heat Non-renewable Resources that do not renew at a sufficient rates in human time-frames. Homework - Complete the Energy Source Summary Assignment and hand-in to Mr. McKennitt (either through the portal or drop-off folder) - Study for your quiz (Chapter 7 and 8) Quiz is on Friday, May 2 nd Science 30 Energy and The Environment (Unit D) Page 14
After you complete the energy source assignment, you may wish to work on this optional review as you are expected to know in detail all the energy sources you researched. You may wish to summarize on a separate sheet for your own notes as part of your review. Note this activity is optional and only for extra review or practice (I am not taking it in) Energy Source Non-renewable or Renewable Where does the energy originate? Advantages of using this source Disadvantages of using this source WIND renewable Unequal solar warming of Earth s surface and atmosphere produces wind. many wind places, relatively cheap, no emissions intermittent, possible hazard to birds and bats, noise, light flickering NUCLEAR BIOMASS FOSSIL FUEL (COAL, PETROLEUM, NATURAL GAS) TIDAL & WAVE SOLAR (Passive and Active) HYDROELECTRIC GEOTHERMAL HYDOGEN FUEL Science 30 Energy and The Environment (Unit D) Page 15