Forensics- Chapter 5

Anything that has mass and occupies space is defined as [blank]

matter

The basic building blocks of all substances are the [blank]

elements

The number of all elements known today are [blank]

104

An arrangement of elements by similar chemical properties is accomplished in the [blank] table

periodic

An [blank] is the smallest particle of an element that can exist

atom

Substances composed of two or more elements are called [blank]

compounds

A [blank] is the smallest unit of a compound formed by the union of two or more atoms

molecule

The physical state that retains a definite shape and volume is a [blank]

solid

A gas [has no,has] definite shape or volume

has no

During the process of [blank], solids will go directly to the gaseous state, bypassing the liquid state

sublimation

The attraction forces between the molecules of a liquid are [more, less] than those in a solid

less

Different [blank] are separated by definite visible boundaries

phases

Carbon containing substances are classified as [blank]

organic

[blank] substances encompasses all non-carbon-containing materials

inorganic

a [blank] analysis describes the identity of a material, and a [blank] analysis relates to a determination of the quantity of a substance

Qualitative and quantitative

The study of the absorption of light by chemical substances is known as [blank]

spectrophotometry

The separation of a mixture's components can be accomplished utilizing the technique of [blank]

chromatography

T or F: Henry's Law describes the distribution between a stationary liquid phase and gas phase

true

The [higher, lower] the solubility of a gas in a liquid, the greater will be its tendency to remain dissolved in that liquid

higher

T or F: In order for chromatography to occur, one phase must be made to move continuously in one direction over a stationary phase

true

A technique that separates mixtures on the basis of their distribution continuously in one direction over a stationary liquid phase and a moving gas phase is [blank]

gas chromatography

The time required for a substance to travel through the gas chromatographic column is a useful identifying characteristic known as [blank]

retention time

Solid materials that are not readily dissolved in solvents for injection into the gas chromatograph can [blank] into numerous gaseous products prior to entering the gas chromatograph

pyrolyze

A major advance of high-performance liquid chromatography is that the entire process takes place at [blank] temperature

room

A technique that uses a moving liquid phase and a stationary solid phase to separated mixtures is [blank]

TLC

Since most chemical compounds are colorless, the final step of the thin layer development usually requires that they be [blank] by spraying with a chemical reagant

visual

The distance a spot has traveled up a thin-layer plate can be assigned a numerical value known as the [blank] value

Rf

T or F: Thin layer chromotography yields the positive identification of a material

false

The migration of materials along a stationary phase under the influence of an electrical potential describes the technique of [blank]

electrophoresis

T or F: Color is a usual indication that substances selectively absorb light

true

The distance between successive identical points on a wave is known as [blank]

wavelength

T or F: Frequency and wavelength are directly proportional to one another

false

Light, xrays, and radio waves are all members of the [blank] spectrum

electromagnetic

Red light is [higher, lower] in frequency than violet light

higher

Light that has all its waves pulsating in unison is called [blank]

lasers

One model of light depicts it as consisiting of energy particles known as [blank]

photons

T or F: The energy of a light particle is directly proportional to its frequency

true

Red light is [more,less] energetic than violet light

less

The selective absorption of electromagnetic radiation by materials [can, cannot] be used as an aid for identification

can

The amount of radiation a substance will absorb is directly proportional to its concentration as defined by [blank] law

beer's

The [blank] is the instrument used to measure and record the absorption spectrum of a chemical substance

spectrophotometer

The function of the [blank] is to select a single frequency of light emanating from the spectrophotometer's source

monochromator

An [ultraviolet, infrared] absorption spectrum provides a unique "fingerprint" of a chemical substance

infrared

The technique of [blank] exposes molecules to a beam of high-energy electrons in order to fragment them

mass spectrometry

T or F: A mass spectrum is normally considered to be a specific means for identifying a chemical substance

true