Ch. 1 Types of Evidence (Exam 1)

Question 1

This is an object that may have a connection with a crime.

Answer 1

What is evidence?

Question 2

What are the 2 purposes of analyzing evidence?

Answer 2

1) Identification
2) Comparison

Question 3

These molecules consist of large numbers of repeated chemical structural units.

Answer 3

What are polymers?

Question 4

These polymers consist of two or more different monomer structures.

Answer 4

What are copolymers?

Question 5

Give examples of the 3 types of copolymers using the letters A & B to represent two different monomeric structures.

Answer 5

1) Block - AAABBB
2) Random - ABBABA (any order is fine)
3) Alternate - ABABAB

Question 6

Give 4 examples of polymers used in packaging.

Answer 6

1) Polyethylene (PE)
2) Polypropylene (PP)
3) Polystyrene (PS)
4) Poly (ethylene terephthalate), or PET

Question 7

Give 3 examples of polymers used for adhesives.

Answer 7

1) Polypropylene (PP)
2) Polyvinyl Chloride (PVC)
3) Acrylic

Question 8

This copolymer is used to manufacture bumper bars.

Answer 8

What is styrene-butadiene (SBR)?

Question 9

This copolymer is used to make tires.

Answer 9

What is styrene-acrylonitrile (SAN)?

Question 10

This polymer is used to make car light enclosures.

Answer 10

What is poly (methyl methacrylate), or PMMA?

Question 11

Fibers can be classified into these two groups.

Answer 11

What are natural and man-made?

Question 12

What are 3 sources of natural fiber?

Answer 12

Animals, plants, & minerals

Question 13

What are the 2 types of man-made fibers?

Answer 13

Synthetic and regenerated

Question 14

This often multi-layered specimen is used to cover a range of surfaces and is composed of pigments, binders, solvents, and additives.

Answer 14

What is paint?

Question 15

This material is produced from fiber pulp, with wood being a major source of this fiber.

Answer 15

What is paper?

Question 16

What is the purpose of a sizing agent in paper manufacturing?

Answer 16

It makes the cellulose component more hydrophobic to prevent the ink from running

Question 17

What 3 pieces of information can ink provide document examiners?

Answer 17

1) If 2 inks have the same origin
2) If 2 inks were made by the same manufacturer
3) When the inks were manufactured

Question 18

In what 3 ways is toner useful in document analysis?

Answer 18

1) Show if 2 documents have the same origin
2) Show the source of a document
3) Show if a document has been altered

Question 19

This material is produced from silica and other metal oxides that are melted at a high temp and quickly cooled to produce an amorphous structure.

Answer 19

What is glass?

Question 20

What is the purpose of a flux in glass production? Give examples of fluxes too.

Answer 20

Lower melting temp
Ex: Na2O & K2O

Question 21

How do fluxes lower the melting point temp of a glass mixture?

Answer 21

They disrupt the Si—–O network in the silica

Question 22

These substances, made of compounds such as CaO & MgO, are added to glass to make it more water resistant.

Answer 22

What are stabilizers?

Question 23

Why are stabilizers needed in glass manufacturing?

Answer 23

The bonds in the Si—–O network weaken as cations migrate out of the matrix in the presence of water

Question 24

This type of soda-lime glass is used to produce Pyrex dishes.

Answer 24

What is borosilicate?

Question 25

This piece of evidence is a complex mixture of minerals and organic matter, as well as man-made materials such as glass.

Answer 25

What is soil?

Question 26

Which is the better analytical method for examining soil samples? Comparison or quantification?

Answer 26

Comparison