Deck 14: Metals, Paint, and Soil

Question 1

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.

Answer 1

A

Question 2

An element is selective in the frequency of light it will absorb. This selectivity is due to its:

A)Number of neutrons.
B)Proton cloud.
C)Atomic mass.
D)Electron energy levels.

Answer 2

D

Question 3

In neutron activation analysis, an element is identified by measuring the energy of emitting:

A)Protons.
B)Electrons.
C)Neutrons.
D)Gamma rays.

Answer 3

D

Question 4

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

A)X rays
B)Gamma rays
C)Beta particles
D)Alpha particles

Question 5

What is NOT part of the composition of paint?

A)Solvent
B)Adhesive
C)Pigment
D)Binder

Question 6

Which coating helps resist UV radiation and acid rain?

A)Electrocoat primer
B)Primer surface
C)Basecoat
D)Clearcoat

Question 7

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)Compounds.
C)Molecules.
D)Isotopes.

Question 8

The emission spectrograph is used to determine the:

A)Mass of a substance.
B)Weight of a substance.
C)Crystalline structure of a substance.
D)Elemental composition of a substance.

Question 9

Neutron activation analysis involves bombarding specimens with neutrons and then measuring the resultant:

A)X rays.
B)Gamma rays.
C)Beta particles.
D)Alpha particles.

Question 10

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)Make
C)Year
D)All of the above

Question 11

A "fingerprint" of an element is obtained by the technique of:

A)Infrared spectrophotometry.
B)Ultraviolet spectrophotometry.
C)Gas chromatography.
D)Emission spectroscopy.

Question 12

Radioactivity is composed of:

A)Alpha particles.
B)Beta particles.
C)Gamma rays.
D)All of the above

Question 13

The nucleus of an atom contains:

A)Neutrons.
B)Neutrons and electrons.
C)Protons and electrons.
D)Protons and neutrons.

Question 14

Paint as physical evidence is most frequently encountered in:

A)Burglary.
B)A hit-and-run.
C)Car theft.
D)Both A and B

Question 15

Which of the following is a non-destructive technique for identifying and quantifying trace elements in a test sample?

A)Carbon arc emission spectrometry
B)ICP emission spectrometry
C)Neutron activation analysis
D)Infrared spectrophotometry

Question 16

Which of the following statements is FALSE?

A)Protons and neutron comprise the nucleus of an atom.
B)The proton has a charge of +1.
C)The neutron has no electrical charge.
D)The electron and proton have the same mass.

Question 17

Atoms having the same atomic number but different atomic masses are called:

A)Isobars.
B)Isotopes.
C)Isotherms.
D)Isomers.

Question 18

Which of the following statements is correct?

A)All atoms of an element have the same atomic mass number.
B)All atoms of an element have the same number of protons.
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.

Question 19

Gamma rays are:

A)Electrons.
B)Protons.
C)Neutrons.
D)Electromagnetic radiation.

Question 20

What type of evidence would be expected to have trace elements?

A)Glass and metal objects
B)Paint and bullet fragments
C)Soil and gun primer particles
D)All of the above

Question 21

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

Question 22

Which would be LEAST useful in identifying a mineral crystal?

A)Size
B)Color
C)Geometric shape
D)Refractive index

Question 23

Alpha particles are a form of radiation consisting of electrons.

Question 24

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

Question 25

Which coat represents the "eye appeal"?

A)Electrocoat primer
B)Primer surface
C)Basecoat
D)Clearcoat

Question 26

What is the logical first step in soil analysis?

A)Examination for presence of debris under low-power magnification
B)Comparison of dried soil sample for color and texture
C)Use of the density-gradient tube technique
D)Examination of minerals and rocks under high-power magnification

Question 27

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

Question 28

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

Question 29

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

Question 30

Paint binders can be chemically analyzed using:

A)TLC.
B)IR spectrophotometry.
C)Pyrolysis GC.
D)Both B and C

Question 31

Paint chips may be individualized to a single source by examining their:

A)Infrared spectra.
B)Ultraviolet spectra.
C)Color and layer structure.
D)Pyrograms.
E)Their relative size.

Question 32

Automobile finishes typically contain which layers?

A)Colorcoat
B)An electrocoat primer, colorcoat, and clearcoat
C)Clearcoat
D)Electrocoat primer and colorcoat

Question 33

Neutrons carry no charge.

Question 34

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

Question 35

Which coating provides resistance to corrosion?

A)Electrocoat primer
B)Primer surface
C)Basecoat
D)Clearcoat

Question 36

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

Question 37

Which property imparts paint with its most distinctive forensic characteristics?

A)Color-layer sequence
B)Color
C)Gloss
D)Texture

Question 38

The polymeric makeup of paint binders can readily be compared by:

A)Emission spectroscopy.
B)Thin-layer chromatography.
C)Microscopy.
D)Pyrolysis gas chromatography.

Question 39

Isotopes have different atomic mass numbers.

Question 40

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

Question 41

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

Question 42

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

Question 43

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

Question 44

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

Question 45

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.

Question 46

ICP emission spectrophotometry can be used to obtain an ________ profile of a questioned bullet fragment for comparison against an unfired bullet found in the possession of the suspect.

Question 47

A(n)________ spectrum shows a series of lines separated by black areas in which each line represents a definite wavelength of frequency.

Question 48

A ________ element is an element found in very small quantities.

Question 49

Elements selectively absorb and emit ________.

Question 50

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.

Question 51

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

Question 52

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

Question 53

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

Question 54

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

Question 55

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

Question 56

The three basic subatomic particles are the proton, electron, and ________.

Question 57

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

Question 58

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

Question 59

An electron moves to a ________-energy orbital when it absorbs energy, such as heat or light.

Question 60

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.

Question 61

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
Atomic mass

Question 62

A(n)________ is a naturally occurring crystalline solid that can be identified by its physical properties.

Question 63

Soil is collected as ________ to preserve a record of the buildup of several layers of soil from different locations over time.

Question 64

When an electron moves to a lower-energy orbital, it ________ energy.

Question 65

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
Electron

Question 66

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

Question 67

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
Atomic number

Question 68

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
Emission spectrum

Question 69

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

Question 70

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

Question 71

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
Isotope

Question 72

Paint specimens are best compared side by side under a ________ microscope.

Question 73

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

Question 74

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

Question 75

The three types of radiation are alpha particles, beta particles, and ________ rays.

Question 76

________ are atoms of the same element that have different numbers of neutrons in their respective nuclei.

Question 77

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
Neutron

Question 78

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
Proton

Question 79

A thorough comparison of paint must include a chemical analysis of the paint's pigments and ________ composition.

Question 80

When comparing paint chips under a microscope, a criminalist looks for color, surface texture, and ________ layer sequence.