chapter 13- metals, paint, and soil

Which is NOT part of the composition of​ paint? A. Solvent B. Binder C. Adhesive D. Pigment

Adhesive

Which of the following statements is​ correct? A. All atoms of an element have the same number of protons. B. All atoms of an element have the same atomic mass number. C. All atoms of an electron have the same number of neutrons. D. All atoms of an element have an equal number of neutrons and electrons.

All atoms of an element have the same number of protons.

After examining small paint chips from an auto accident scene and using the PDQ​ database, the crime lab worker can determine the​ ________ of the vehicle. A. Model B. Year C. Make D. All of the above

All of the above

Radioactivity is composed​ of: A. Beta particles. B. Alpha particles. C. Gamma rays. D. All of the above

All of the above

What type of evidence would be expected to have trace​ elements? A. Paint and bullet fragments B. Soil and gun primer particles C. Glass and metal objects D. All of the above

All of the above

Automobile finishes typically contain which​ layer(s)? A. Electrocoat primer and colorcoat B. An electrocoat​ primer, colorcoat, and clearcoat C. Clearcoat D. Colorcoat

An electrocoat​ primer, colorcoat, and clearcoat

Paint as physical evidence is most frequently encountered​ in: A. Burglary. B. A​ hit-and-run. C. Car theft. D. Both A and B

A​ hit-and-run.

Which coat represents the​ "eye appeal"? A. Basecoat B. Clearcoat C. Primer surface D. Electrocoat primer

Basecoat

Which coating helps resist UV radiation and acid​ rain? A. Electrocoat primer B. Primer surface C. Basecoat D. Clearcoat

Basecoat

Paint binders can be chemically analyzed​ using: A. TLC. B. IR spectrophotometry. C. Pyrolysis GC. D. Both B and C

Both B and C (IR Spectrophotometry and Pyrolysis GC)

Paint chips may be individualized to a single source by examining​ their: A. Color and layer structure. B. Ultraviolet spectra. C. Relative size. D. Pyrograms. E. Infrared spectra.

Color and layer structure.

What is the logical first step in soil​ analysis? A. Comparison of dried soil sample for color and texture B. Examination for presence of debris under​ low-power magnification C. Examination of minerals and rocks under​ high-power magnification D. Use of the​ density-gradient tube technique

Comparison of dried soil sample for color and texture

In a simple emission​ spectrograph, excitation of the specimen under investigation is accomplished with​ a(n): A. Electrical arc. B. Inductive magnetic field. C. Hot plasma torch. D. Activated prism.

Electrical arc.

Which coating provides resistance to​ corrosion? A. Electrocoat primer B. Clearcoat C. Primer surface D. Basecoat

Electrocoat primer

Gamma rays​ are: A. Electrons. B. Electromagnetic radiation. C. Neutrons. D. Protons.

Electromagnetic radiation.

An element is selective in the frequency of light it will absorb. This selectivity is due to​ its: A. Proton cloud. B. Atomic mass. C. Electron energy levels. D. Number of neutrons.

Electron energy levels.

The emission spectrograph is used to determine​ the: A. Mass of a substance. B. Weight of a substance. C. Elemental composition of a substance. D. Crystalline structure of a substance.

Elemental composition of a substance.

A​ "fingerprint" of an element is obtained by the technique​ of: A. Emission spectroscopy. B. Infrared spectrophotometry. C. Gas chromatography. D. Ultraviolet spectrophotometry.

Emission spectroscopy.

A continuous spectrum is most helpful in identifying a particular element because it serves as a unique​ "fingerprint" of an element. True False

False

All atoms of an element have the same number of neutrons. True False

False

Alpha particles are a form of radiation consisting of electrons. True False

False

Emission spectroscopy measures the frequency of light emitted by an atom when one of its electrons moves to a higher orbital. True False

False

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

False

Isotopes are atoms of the same element that have different numbers of protons in their respective nuclei. True False

False

It is not necessary that the collected paint from a vehicle involved in a​ hit-and-run accident be close to the area of the car suspected of being in contact with the victim. True False

False

Neutron activation analysis is favored in crime laboratories because of its low cost and ease of use. True False

False

Surface texture is the most important of the characteristics that a criminalist looks for when comparing paint chips. True False

False

The first step in a forensic soil comparison is analysis of the size of the particles. True False

False

The minerals found in different soil samples cannot effectively be used to determine whether or not they have the same origin. True False

False

The number of protons in the nucleus of an atom is called the atomic mass number. True False

False

In neutron activation​ analysis, an element is identified by measuring the energy of​ emitting: A. Electrons. B. Gamma rays. C. Protons. D. Neutrons.

Gamma rays

Neutron activation analysis involves bombarding specimens with neutrons and then measuring the​ resultant: A. Alpha particles. B. Gamma rays. C. ​X-rays. D. Beta particles.

Gamma rays

Atoms having the same atomic number but different atomic masses are​ called: A. Isobars. B. Isotopes. C. Isomers. D. Isotherms.

Isotopes

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: A. Elements. B. Molecules. C. Compounds. D. Isotopes.

Isotopes

Which of the following is a​ non-destructive technique for identifying and quantifying trace elements in a test​ sample? A. Neutron activation analysis B. Carbon arc emission spectrometry C. ICP emission spectrometry D. Infrared spectrophotometry

Neutron activation analysis

The​ ________ properties of​ crystals, such as refractive index and​ birefringence, provide points of identification that help characterize them. A. Optical B. Chemical C. Amorphous D. Physical

Optical

The most abundant element of the​ earth's crust​ is: A. Oxygen. B. Carbon. C. Aluminum. D. Hydrogen.

Oxygen

The nucleus of an atom​ contains: A. Protons and neutrons. B. Protons and electrons. C. Neutrons. D. Neutrons and electrons.

Protons and neutrons.

The polymeric makeup of paint binders can readily be compared​ by: A. Emission spectroscopy. B. Microscopy. C. ​Thin-layer chromatography. D. Pyrolysis gas chromatography.

Pyrolysis gas chromatography.

Which would be LEAST useful in identifying a mineral​ crystal? A. Geometric shape B. Color C. Size D. Refractive index

Size

Which of the following statements is​ false? A. The electron and proton have the same mass. B. The neutron has no electrical charge. C. The proton has a charge of​ +1. D. Protons and neutron comprise the nucleus of an atom.

The electron and proton have the same mass.

After the paint has been applied to a​ surface, the solvent evaporates. True False

True

An atom has a net zero electrical​ charge, which indicates that it contains the same number of protons and electrons. True False

True

Emission, spectroscopy and neutron activation analysis do not provide any information as to how the elements are combined into compounds. True False

True

Gamma rays are a​ high-energy form of electromagnetic radiation. True False

True

Isotopes have different atomic mass numbers. True False

True

Mutilated bullets are often not suitable for traditional microscopic comparisons against an exemplar​ test-fired bullet. True False

True

Neutrons carry no charge. True False

True

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

True

The investigator should not try to remove trace paint evidence found on a tool but package the tool for laboratory examination instead. True False

True

The major advantage of neutron activation analysis is that it provides a nondestructive method for identifying and quantitating trace elements. True False

True

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

True

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. True False

True

​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. True False

True

Which type of radiation is NOT given off by radioactive​ decay? A. Gamma rays B. Alpha particles C. Beta particles D. ​X- rays

X- rays

ICP emission spectrophotometry can be used to obtain​ a(n) ________________________ profile of the questioned bullet fragment for comparison against an unfired bullet generally found in the possession of the suspect.

elemental

Which property imparts paint with its most distinctive forensic​ characteristics? A. Gloss B. Color C. Texture D. ​Color-layer sequence

​Color-layer sequence