Exam 14: Metals, Paint, and Soil

________ as physical evidence is most frequently encountered in hit-and-run cases.

Pyrolysis gas chromatography produces a pattern or ________ of the polymers that identifies the specific chemical makeup of the binder.

The variety of coatings applied to the body of an automobile adds significant diversity to automobile paint and contributes to the forensic significance of automobile paint comparisons.

Which type of radiation is NOT given off by radioactive decay?

A(n)________ spectrum shows a continuous band of colors all blending into one another.

Alpha particles are a type of radiation composed of ________ atoms minus their orbiting electrons.

Match the word in Column 1 to its definition in Column 2. Each answer can only be used once. A)An atom differing from another atom of the same element in the number of neutrons in its nucleus B)A type of emission spectrum showing a series of lines separated by black areas C)A particle with no electrical charge that is one of the basic structures in the nucleus of an atom D)The state in which an atom absorbs energy and an electron moves from a lower to a higher energy level E)A negatively charged particle that is one of the fundamental structural units of the atom F)Light emitted from a source and separated into its component colors or frequencies G)The number of protons in the nucleus of an atom H)The sum of the number of protons and neutrons in the nucleus of an atom I)The path of electrons as they move around the nuclei of atoms J)A positively charged particle that is one of the basic structures in the nucleus of an atom -Line spectrum

A suspect has been found miles from the scene of a murder. Soil is found adhering to the suspect's shoe. Describe the proper collection and preservation of soil evidence that will permit a thorough comparison of the soil on the shoe to soil at the crime scene.

Describe the proper collection and preservation of paint evidence from an automobile suspected of being involved in a hit-and-run incident. Paint that is foreign to the suspect automobile is observed on the hood.

Standard/reference soil samples should be collected at the site of the crime at various intervals within a 100-foot radius of the crime scene.

________ is the emission of radiation that accompanies the spontaneous disintegration of unstable nuclei.

Which coating provides resistance to corrosion?

Gamma rays are:

The presence of trace elements is useful because they provide markers that may establish the source of a material.

If soil is found adhering to an object, the investigator should remove the soil particles from the object and send them to the laboratory.

Explain how the analysis of trace elements was important to the investigation of the assassination of President John. F. Kennedy.

The atoms of hydrogen, deuterium, and tritium all have the same number of protons, but differ in the number of neutrons they possess. These substances are:

Using knowledge about the operation of ICP emission spectrophotometry, determine whether it could or could not be utilized for the following analyses: a. analysis of metals in wine to determine area of origin b. detection of arsenic in a food sample c. carbon dating of a tree pulp sample d. analysis of trace metals in soil samples to determine area of origin e. analysis of hydrocarbons in a fuel mixture used to propel a hot air balloon f. identification of polymer binders in an automobile paint sample g. authentication of a bronze age weapon by component metal analysis

The concentration of the absorbing element is directly proportional to the quantity of the light absorbed.

Paint as physical evidence is most frequently encountered in: