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Return to Ms. B when finished.
Ch. 11 – Trace Elements: Metals, Paint, and Soil
Any time you write your answers on a separate sheet of paper, you will need to do one of two things
 Copy the question exactly as stated on the worksheet then write your answer. Your answer
does not need to be in a complete sentence.
 Or, restate the question in your answer. This needs to be in a complete sentence
1. What is a trace element and why are trace elements important in analyzing physical evidence?
2. Explain how the analysis of trace elements was important to the investigation of the
assassination of President John F. Kennedy.
3. Describe the difference between a continuous spectrum and a line spectrum. Which is most
helpful in identifying a particular element and why?
4. What is ICP and why is it used to analyze mutilated bullets?
5. What causes an electron to move to a higher energy level? What happens when an electron
moves to a lower energy level?
6. What is measured by emission spectroscopy?
7. List two ways in which isotopes differ from one another.
8. What causes radioactivity? List and define the three types of radiation.
9. How does a nuclear reactor generate radioactive elements?
10. Describe the process of nuclear activation analysis. How does the process allow a forensic
scientist to identify an isotope?
11. What is the main advantage and main weakness of neutron activation analysis?
12. What three features of paint does a forensic scientist compare using a microscope?
13. What is the greatest shortcoming in using layer structure to analyze paint evidence?
14. How is pyrolysis gas chromatography used to distinguish one paint binder from another?
15. How is PDQ used in identifying paint samples?
16. How can soil evidence be valuable even if the site of the crime has not been ascertained?
17. What is a mineral and how can minerals be important in the comparison of soil samples?