EX1; Characteristics of X-Rays

Question 1

What are the two main attributes of X-rays

Answer 1

ionization

excitation

Question 2

When does ionization occur

Answer 2

when an atom gains or looses an electron

Question 3

This occurs when particulate or electromagnetic radiation energy is greater than the binding energy

Answer 3

ionization

Question 4

This is the negative ion in ionization

Answer 4

the ejected ion

Question 5

This is the position ion in ionization

Answer 5

the remainder of the atom minus the ejected ion

Question 6

The radiation that causes ionization (usually in biologic molecules) is called what

Answer 6

ionization radiation

Question 7

This is when the transferred energy is not enough to overcome the binding energy, the electron is not ejected from its orbit

Answer 7

excitation

Question 8

What occurs upon excitation

Answer 8

the electron receiving the extra energy is raised to a higher energy level within its orbit, then instantaneously gives up this excess energy and returns to its normal energy level

Question 9

All the effects of x-rays are due to its ability to do what

Answer 9

ionize

Question 10

Penetrability is related to

Answer 10

photon energy (direct)
number (direct)
atomic number, thickness, and density of absorber (inverse)

Question 11

What are the three salient properties

Answer 11

photographic effects
fluorescent effects; useful in intensifying screens
biologic effects

Question 12

This type of wave is a salient property

Answer 12

invisible, highly penetrating electromagnetic wave
heterogenous; variable wavelengths and energy photons
traveling at the speed of light

Question 13

What kind of charge is a salient property

Answer 13

neutral charge; cannot be deflected

Question 14

What direction from the source is a salient property

Answer 14

in straight lines, tend to diverge from focal spot

Question 15

salient property; capable of ionizing what

Answer 15

gas

Question 16

salient property; produces a latent image on what

Answer 16

on an image receptor which can be processed

Question 17

What is the useful wavelength range in dentistry; salient property

Answer 17

1-5 angstroms

Question 18

salient property; produced chemical and biologic changes in what

Answer 18

living tissues

Question 19

Low energy x-rays are used in which type of radiology

Answer 19

diagnostic

Question 20

high energy x-rays are used in which type of radiation

Answer 20

radiation therapy

Question 21

Intensity (amount or quantity) or radiation is inversely proportional to what

Answer 21

the square of the distance between the source and point of measure

Question 22

What are the three primary means of beam absorption

Answer 22

photoelectric absorption
compton scattering
coherent scattering

Question 23

About what percentage of primary photons pass through without any interaction

Answer 23

9%

Question 24

This is when the incident photon interacts with an inner skill electron (K shell), overcoming the binding energy

Answer 24

photoelectric absorption

Question 25

The electron that is ejected during photoelectric absorption is called what

Answer 25

photoelectron or recoil electron

Question 26

What does the ejected electron acquire

Answer 26

the remainder of the kinetic energy

Question 27

This is when the incident photon interacts with the outer electron, overcoming binding energy, ejecting the electron

Answer 27

compton absorption

Question 28

What becomes of the kinetic energy in compton absorption

Answer 28

the compton electron acquires part of it and the remainder is given off as a scattered photon

Question 29

What does the compton electron cause

Answer 29

secondary and tertiary ionizations

major source of scatter radiation

Question 30

This is when low energy photons pass near outer electron of an atom

Answer 30

coherent scattering

Question 31

The electron in coherent scattering does what

Answer 31

vibrates at the same frequency as incident photon

Question 32

What becomes of the kinetic energy in coherent scattering

Answer 32

entire energy is given off as scattered photon, which is usually absorbed by the tissues