Module 8 Exam Review



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Module 8 Exam Review

This review is neither a replica of the exam nor does it contain every concept in the module or what may be on the exam. This contains only the concepts in the regular lessons. It is always best practice to review all lessons and assessments. Resubmitting is a great way to review/learn and improve your grade. In this review, questions 1 – 21 are the general topics for the multiple choice type questions on the module exam; questions 22-25 are covered as essays on the exam. There are approximately 30 questions (about 5 are essays) on the regular exam; approximately 38 questions (about 8 are essays) on the honors exam. The number in parenthesis corresponds to the lesson for that question. None of the honors lessons are in this review. The answer key is after the review.



Multiple Choice Topics

  1. Explain the difference between chemical and nuclear reactions. (8.01)




  1. Compare and contrast beta particles, alpha particles and gamma rays. (8.01)




  1. Put the three types of radioactive particles in order of increasing penetrating power. (8.01)




  1. Write the reaction for the alpha decay of Americium-241.(8.01)




  1. Write the reaction for the beta decay of Thallium-210. (8.01)




  1. What can happen if a neutron strikes a heavy atom and what is the scientific term for this process? (8.02)




  1. Briefly explain how a nuclear power plant operates. (8.02)




  1. Is the radioactive waste from a power plant safe? (8.02)




  1. What is a major disadvantage of fusion reactions? (8.02)




  1. What are greenhouse gases? (8.03)




  1. Define renewable resources and describe five examples.




  1. Define non-renewable resources and give at least two examples.




  1. List at least three common air and water pollutants. (8.04)




  1. What is a disadvantage of ozone depletion? (be able to discuss all 6 “Negative Impacts” from the lesson: oil spills, groundwater, waste disposal, ozone depletion, air and water pollution). (8.04)




  1. Describe the pros of recycling. (8.04)




  1. What is one thing we can do to help reduce the impact of pollution on our environment? (8.04)




  1. What are three things we can do to be more energy efficient? (8.04)




  1. Describe a few characteristics of carbon? (8.05)




  1. List the four types of organic compounds we learned in the lesson. (8.05)



  1. What are five biotechnologies we studied in the lesson? (8.06)




  1. Which biotechnology can compare DNA sequences? (8.06)

Essay Topics


  1. If it takes 150 days for a sample to decay from 80 grams to 10 grams, what is the half-life of this isotope? (8.01)




  1. Describe the pros and cons of nuclear power plants. (8.02)




  1. Describe two negative impacts on the environment and describe how we can reduce pollution. (Be able to describe how to reduce all types of pollution from the lesson) (8.04)




  1. What are three things we can do to be more energy efficient? (8.04)



Module 8 Exam Review ANSWER KEY

Multiple Choice Topics

  1. Explain the difference between chemical and nuclear reactions. (8.01)

Chemical reactions rearrange atoms forming new bonds; they do not create new atoms or release particles. Chemical reactions occur because of valence electrons.
Nuclear reactions will form new atoms with new identities (atomic number). Nuclear reactions occur because of unstable nuclei. Nuclear reactions release a significantly higher amount of energy due to the forces that hold the nucleus together.


  1. Compare and contrast beta particles, alpha particles and gamma rays. (8.01)

Alpha particles are basically a helium nucleus. They have a charge of +2 as they have two protons and two neutrons. In alpha decay, the radioactive element’s atomic number decreases by two and its mass decreases by four. Alpha particles are the safest of the three as your skin will stop them.
Beta particles are often referred to as high-speed electrons. They have little mass and a charge of -1. They are released from a nucleus when a neutron breaks apart into a proton and an electron. They are faster than alpha particles and can be a little more dangerous if they are ingested. Beta particles are energetic enough to penetrate your skin. In beta decay, the radioactive element ends up with one extra proton and one less neutron. So, the mass remains the same, but the atomic number increases by one.
Gamma rays are very dangerous and are emitted along with alpha and beta particles. They are very high energy and high frequency photons. They have no mass and no charge. The radioactive element’s atomic number and mass does not change. Severe damage can occur to organs if exposed to gamma rays. Thick layers of lead or concrete will stop gamma rays.




  1. Put the three types of radioactive particles in order of increasing penetrating power. (8.01)

Gamma is most energetic, thus will penetrate the most. Beta is the next most dangerous. Alpha particles are the least energetic.

Alpha < beta < gamma




  1. Write the reaction for the alpha decay of Americium-241.(8.01)

An alpha particle is basically a helium nucleus. So, we write it:

Since this is an alpha decay problem, the alpha particle is a product. We then have to figure out what is ‘left’ to see what the other product is.



An alpha particle has a mass of 4. So, Americium’s mass is reduced by 4 (241 -4 = 237). An alpha particle has 2 protons, so Americium has lost two protons (95 – 2 = 93). So, our mystery particle has an atomic number of 93. Using the periodic table, atomic number 93 belongs to Np.





  1. Write the reaction for the beta decay of Thallium-210. (8.01)

A beta particle is a high speed electron. So, we write it:
Since this is a beta decay problem, the beta particle is a product. We then have to figure out what is ‘left’ to see what the other product is.

A beta particle has no mass, so the mass of the mystery particle will be the same of Thallium. The beta particle is formed from a neutron breaking down into a proton and an electron. The radioactive element keeps the new proton, thus the atomic number will increase by one. Our mystery particle will have an atomic number of 82.

Using the periodic table, atomic number 82 belongs to Pb.




  1. What can happen if a neutron strikes a heavy atom and what is the scientific term for this process? (8.02)

Sometimes, when a neutron strikes a heavy atom, the atom will absorb it, which causes it to become unstable. The heavy atom can oftentimes split into two or more smaller atoms. This is called nuclear fission.


  1. Briefly explain how a nuclear power plant operates. (8.02)

The nuclear power plant is a big nuclear fission reaction. The plants use uranium, a radioactive isotope, which undergoes fission. Neutrons bombard the uranium, which starts a chain reaction. The reaction is controlled by neutron-absorbing rods. They are known as control rods. The temperature of the fuel must remain under control and not allowed to increase too much. Therefore, the water around the fuel (uranium) is held under high pressure to avoid boiling.
The energy released from the fission reaction travels to a second water system and is used to boil water which produces steam. The steam then turns a large turbine. The turbine is connected to a generator where mechanical energy is turned into electrical energy.
The electrical energy then leaves the generator and flows to the power lines that we see.


  1. Is the radioactive waste from a power plant safe? (8.02)

No, it is not. It is still radioactive and must be handled carefully. This is one of the greatest concerns. As of now, there is no disposal option that has been used or proposed that is considered ideal and without risks or hazards.


  1. What is a major disadvantage of fusion reactions? (8.02)

The major disadvantage is that fusion reactions are very difficult to initiate and control. The nuclei of the very small atoms experience a very strong repulsion. Therefore, we must use very high speeds, often due to extremely high temperatures in order to overcome the positive charges of the nuclei to get them to collide and react. Fusion is not used in power plants as we currently do not have an efficient way to initiate and control it.


  1. What are greenhouse gases? (8.03)

Greenhouse gases are linked to global warming. The main greenhouse gas is carbon dioxide, CO2.


  1. Define renewable resources and describe five examples.

Renewable resources are natural resources that can be replaced at the same rate or faster than they are used. Some examples include hydropower, wind power, solar energy, biofuel and geothermal energy are a few examples.
Hydropower is produced when water falls through openings in a dam or when a river current applies pressure to turbine blades.
Wind power converts kinetic energy of wind into electricity. Three disadvantages of wind power are that the turbines require a lot of space. It is unreliable due to the uncertainly and inconsistency of the weather. And, it is expensive to build and maintain.
Solar power converts energy from the sun into electrical energy. A disadvantage is that we must store the energy in large batteries called photovoltaic cells. These cells have low efficiency, can be expensive and require large surface areas.
Biofuel (biomass) makes use of garbage (wood, animal dung, agricultural waste). A disadvantage of biofuel is that it would require a large amount of land to replace nonrenewable resources.
Geothermal power comes from the heat buried beneath earth’s surface.



  1. Define non-renewable resources and give at least two examples.

Nonrenewable resources are the natural resources that are used at a faster rate than they can be replaced.
Fossil fuels are the world’s largest supplier of energy. They are used in coal, oil and natural gas. A major disadvantage, other than they are nonrenewable, is that they have been linked to pollution which affects the air, water and climate.
Burning coal accounts for about half of the electricity generated in the U.S. It is the most common energy source in the U.S. Two disadvantages are that burning coal produces CO2 gas and contributes to acid rain.
Oil/Petroleum is the world’s largest energy source. A major disadvantage is that it contributes to acid rain.
Natural gas works similarly to a nuclear power plant. Natural gases can be burned which produces the hot gases needed to turn turbines which generates electricity. It is the 2nd most common energy source in the U.S. Unfortunately, natural gas can be harmful to the environment as it produces CO2 gas which has been linked to global warming.


  1. List at least three common air and water pollutants. (8.04)

Nitrates and phosphates from sewage and fertilizer are common water pollutants. Heat from factories and power plants can be a waterpollutant as it can cause aquatic death. The air is polluted from carbon dioxide released from burning waste, using gasoline dependent automobiles. The air can be polluted by particulate matter, carbon dioxide, nitrogen oxides, lead and sulfur dioxide.


  1. What is a disadvantage of ozone depletion? (be able to discuss all 6 “Negative Impacts” from the lesson: oil spills, groundwater, waste disposal, ozone depletion, air and water pollution). (8.04)

Our Ozone layer, which is produced in the stratosphere, protects us from the sun’s harmful UV rays. There are chemicals, such as CFCs, carbon tetrachloride and methyl chloroform that we make when we burn trash and use gasoline dependent automobiles.


  1. Describe the pros of recycling. (8.04)

Recycling reduces energy and saves natural resources. We can recycle paper, aluminum, glass and rubber. Recycling does include purchasing or donating clothes and furniture to charities and thrift stores. This will reduce the amount of substance in our landfills. It requires less energy to make something using recycled materials than to make it from new materials.


  1. What is one thing we can do to help reduce the impact of pollution on our environment? (8.04)

We can use biological methods, enhanced technology and storage of fuel and waste products to reduce some of the pollution created.



  1. What are three things we can do to be more energy efficient? (8.04)

We can use fuel-efficient cars, compact fluorescent light bulbs, and energy-efficient appliances.


  1. Describe a few characteristics of carbon. (8.05)

Carbon atoms can bond with other carbon atoms in very long chains. Carbon has four valance electrons, which means it will form no more than four covalent bonds. Carbon can form single, double and a triple bond. Carbon can bond to form chains, rings, plates or networks. Diamond, the hardest material known to man, and graphite are two pure forms of carbon. Organic compounds are those compounds that contain carbon. (FYI-If you have a chemical that does not have carbon in it, we call it inorganic)


  1. List the four types of organic compounds we learned in the lesson. (8.05)

In the lesson, we learned that there are many organic substances in the world. The lesson highlighted five of the categories.


  • Hydrocarbons are organic compounds that contain only hydrogen and carbon.

  • Alcohols are organic compounds that has a hydroxyl group (OH) bonded to a carbon (C-O-H).

  • Ethers are organic compounds that ave an oxygen atom sandwiched in between two carbon atoms (-C-O-C-)

  • Amines are organic compounds that have a nitrogen bonded to a carbon (-C-N-)




  • The carbonyl group consists of a carbon atom double bonded to an oxygen atom: There are many categories of organic compounds that contain the carbonyl group: ketones, aldehydes, amides, carboxylic acids and esters.



  • Carbohydrates are made of carbon, hydrogen and oxygen atoms.

  • Polymers are extremely long molecule chains that consist of repeating atoms.



  1. What are five biotechnologies we studied in the lesson? (8.06)

The five biotechnologies are agriculture, forensics, genetic research, drug research, and vaccines and medicines


  1. Which biotechnology can compare DNA sequences? (8.06)

The field of forensics can use DNA to relate victims to crime scenes and suspects.
Essay Topics


  1. If it takes 150 days for a sample to decay from 80 grams to 10 grams, what is the half-life of this isotope? (8.01)

Half-life is the time it takes for half of your sample to decay.
We start with 80 grams.

One-half of 80 grams is 40 grams (1st half-life)

Half of 40 grams is 20 grams (2nd half-life)

Half of 20 grams is 10 grams (3rd half-life)


It took 3 half-lives to decay from 80 g to 10 g. The total time it took was 150 days.

150 days / 3 half-lives = 50 days



The half-life is 50 days


  1. Describe the pros and cons of nuclear power plants. (8.02)

The benefit of nuclear power plants is that they do not produce atmospheric pollutants and greenhouse gases. A negative aspect is the disposal of wastes. As of now, there is no disposal option that has been used or proposed that is considered ideal and without risks or hazards.


  1. Describe two negative impacts on the environment and describe how we can reduce pollution. (Be able to describe how to reduce all types of pollution from the lesson) (8.04)

One of the many ways we contribute to pollution is from pesticides and fertilizers, which can contaminate the groundwater. Carbon monoxide, CO, is another pollute we create when the carbon in fuel is not burned completely (incomplete combustion). CO gas can pollute the air and cause death if it gathers in an enclosed space without ventilation.
There are many ways to reduce pollution. Depending on the type of pollution, we can use reduce the use of fossil fuels, limit the use of fertilizers, repair equipment and automobile exhaust, limit our use of CFCs, prevent oil spills and reduce heat emitted by industry to name only a few.


  1. What are three things we can do to be more energy efficient? (8.04)

We can use fuel-efficient cars, compact fluorescent light bulbs, and energy-efficient appliances.


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