Unit 2: Test

NAME ______________________________________

REVIEW TEST • UNIT 2

Directions: Circle the letter of the answer that best completes the statement given.

1. Ionizing radiation is called “ionizing” because:
   
   
   1. it is emitted by charged particles called ions.
   2. it is everywhere.
   3. we can detect it with our senses.
   4. it produces charged particles called ions in materials it penetrates.
      
      
2. Some important forms of ionizing radiation are:
   
   
   1. high-frequency sound waves.
   2. gamma rays and X-rays.
   3. microwaves and radar.
   4. ultraviolet light from grow lamps.
      
      
3. An important form of non-ionizing radiation is:
   
   
   1. gamma rays.
   2. visible light.
   3. X-ray particles.
   4. beta particles.
      
      
4. The least penetrating form of ionizing radiation is:
   
   
   1. alpha particles.
   2. beta particles.
   3. gamma rays.
   4. electrons.
      
      
5. The form of ionizing radiation that deposits the most energy per unit path (unit of pathway) in human tissue is:
   
   
   1. alpha particles.
   2. beta particles.
   3. X-rays.
   4. gamma rays.
      
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6. A given exposure to gamma rays will have the least effect if it is received:
   
   
   1. all at once.
   2. in two exposures a few minutes apart.
   3. in several exposures over a period of hours.
   4. in several exposures over a period of weeks or months.
      
      
7. The spontaneous emission of fast-moving particles and rays by an atom is called:
   
   
   1. atomization.
   2. spontaneous combustion.
   3. current emissions.
   4. radioactivity.
      
      
8. Nuclides that spontaneously emit ionizing radiation are often called:
   
   
   1. radiators.
   2. radiation.
   3. radionuclides.
   4. radio transmitters.
      
      
9. For people living in the United States, the average annual exposure to ionizing radiation from all sources is:
   
   
   1. 20 millirem.
   2. 55 millirem.
   3. 360 millirem.
   4. 500 millirem.
      
      
10. The average U.S. resident receives the highest percent of exposure to ionizing radiation from:
    
    
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    1. medical diagnosis and treatment.
    2. nuclear power plants and nuclear waste.
    3. transportation of nuclear materials.
    4. natural sources (rocks, soil, cosmic radiation, radon).
       
       
11. If your family found an unacceptable amount of radon present in your home, the best way to control exposure would be:
    
    
    1. move away.
    2. close all the doors and windows.
    3. improve your home’s ventilation.
    4. install a humidifier in your basement.
       
       
12. Two isotopes present in the food we eat that contribute the most to our internal radiation exposure are:
    
    
    1. potassium-40 and carbon-14
    2. tritium-234 and radon-222.
    3. uranium-234 and thorium-230.
    4. Iodine-131 and cesium-137.
       
       
13. The half-life of a radionuclide is the time in which:
    
    
    1. a single radioactive atom loses half its radioactivity.
    2. a quantity of a radioactive substance loses half its radioactivity.
    3. a quantity of a radioactive substance loses half its mass.
    4. a nucleus is divided in half.
       
       
14. The half-life of a radionuclide is the time in which it has a _______ chance of decaying.
    
    
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    1. 25%
    2. 50%
    3. 75%
    4. 100%
       
       
15. People can achieve protection from exposure to radiation by:
    
    
    1. increasing exposure time to a particular source.
    2. decreasing distance from the source.
    3. increasing shielding.
    4. decreasing shielding.
       
       
16. Which of the following best represents a gamma ray?
    
    
    1. 
    2. 
    3. 
    4. 
       
       
17. We assume that there is some risk even for low exposures to ionizing radiation because:
    
    
    1. there are a lot of data that show that there is an effect.
    2. we cannot prove that there is no effect.
    3. no other substances cause similar effects.
    4. effects of high exposures prove effects at low exposures.
       
       
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18. Which of the following does NOT travel at the speed of light?
    
    
    1. beta particle
    2. radar
    3. visible light
    4. radio wave
       
       
19. There is general agreement among scientists about the effects on the body from:
    
    
    1. both high and low exposures to ionizing radiation.
    2. neither high nor low exposures to ionizing radiation.
    3. high exposures to ionizing radiation received in a short time.
    4. low exposures to ionizing radiation received over a long time.
       
       
20. The process in which an atom emits particles and is transformed into a different isotope is:
    
    
    1. spontaneous decay.
    2. random decay.
    3. transformation.
    4. radioactive decay.
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Answer Key [pdf]