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Chapter 20: Radiation Processes
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1. Radiation is carried by a unit called a(n) ____, and is in either wave or particle form.
2. Materials that are ____, like uranium, radium, thorium, and actinium emit photons of energy and/or particles as the
nuclei disintegrate and decrease in mass.
3. When the number of neutrons in the nucleus of an atom changes, the mass of the element is different, forming a(n)
____ of the original element.
4. The unit of energy carried by a single photon is called a ____.
5. Heavy, slow-moving masses containing a double positive charge are called ____.
6. When alpha particles strike other atoms, their double positive charge removes one or more electrons, leaving the atom
or molecule in a dissociated or _____ state.
Chapter 20: Radiation Processes
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7. Electrons ejected from the nuclei of atoms at a very high speed and energy are called ____.
8. Short, very high-frequency electromagnetic waves with no electrical charge are ____.
9. This diagram suggests which type of radiation penetrates most deeply?
10. Which uncharged particles may collide with atomic nuclei, resulting in alpha and gamma radiation?
11. A commercially available radioisotope source that produces ionizing radiation is ____.
Chapter 20: Radiation Processes
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12. What is the primary ionizing source used for radiation processing?
electron beam accelerators
burnt uranium slugs from fission reactor waste
13. Which type of radiation is often used in thermoforming?
14. The process of scission does damage to plastics by ____.
15. When radiation causes long linear plastics to break into short segments, with the plastics losing strength as a result of
this breaking, it produces symptoms such as ____.
16. What is an example of a plastics that benefits from controlled, limited irradiation, with the result of elevating the
softening temperature above that of boiling water?
17. Today, radiation processing is most often done with electron machines or radioisotope sources such as ____.
Chapter 20: Radiation Processes
Copyright Cengage Learning. Powered by Cognero.
18. Ultraviolet treatment may improve such surface characteristics as resistance to ____.
19. Which process, illustrated in this depiction, shows a process for creating polymers that may have very unique
features?
depolymerization of plastics
20. Irradiation of some cellulosic textiles has aided in the development of ____ fabrics.
21. What is a disadvantage of radiation processing?
physical contact is needed
machine sources may be difficult to control