lesson 7 and 8

Question 1

the process of removing of
electrons from the orbital of an atom

Answer 1

IONIZATION

Question 2

the process of temporary removal of electrons from the orbital of an atom or vibration of the electrons of the atom.

Answer 2

EXCITATION

Question 3

radiation that during its passage through an object has been deviated in direction.

Answer 3

SCATTER RADIATION

Question 4

radiation produced when an outer shell electron jumps into inner shell.

Answer 4

CHARACTERISTIC RADIATION

Question 5

radiation produced when high speed of electrons are suddenly stopped or decelerated.

Answer 5

BREMSSTRAHLUNG RADIATION

Question 6

positively charged electron.

Answer 6

POSITRON

Question 7

distance between two
succeeding wave crests.

Answer 7

WAVELENGTH

Question 8

● the incident photon interacts with a
target atom, causing it to become
excited
● the incident photon wavelength(λ)
equals the excess energy photon
wavelength(λ’)
● undergoes a change in direction without
a change in wavelength
● does not cause ionization, it only cause
excitation
● the target atom releases the excess
energy as secondary or scatter radiation
● it causes film fog
● it occurs below 10 keV

Answer 8

CLASSICAL OR COHERENT SCATTERING

Question 9

a single electron is involved in the interaction.

Answer 9

THOMPSON SCATTERING

Question 10

results from a cooperative interaction with all the electrons of an atom.

Answer 10

RAYLEIGH SCATTERING

Question 11

● an interaction of x-ray with outer-shell
electron that not only scatters the photon but reduces its energy and
ionizes the atom as well
● produces secondary or scatter radiation
● causes film fog
● occurs in moderate energy x-rays

Answer 11

COMPTON EFFECT/INCOHERENT
SCATTERING

Question 12

Compton effect yields three products:

Answer 12

1. an ion pair
2. a positive atom
3. a negative electron(recoil electron)

Question 13

● undergo ionizing interaction with inner
shell electron of the target atom, so that
the photon is not scatter but totally
absorbed
● also called photon-absorption interaction
● can not occur unless the incident photon
has energy equal to or greater than the
electron binding energy of the atom

Answer 13

PHOTOELECTRIC EFFECT

Question 14

● it is the strength of attachment of
electron to the nucleus
● the closer an electron to the nucleus,
the more tightly it is bound
● the greater the total no. of electrons in
an atom, the more tightly each is bound
● it takes more energy to ionize a large
atom than a small atom

Answer 14

ELECTRON BINDING ENERGY

Question 15

Photoelectric effect yields three products:

Answer 15

1. a characteristic radiation
2. a negative ion(photoelectron)
3. a positive ion(an atom deficient of
   one electron)

Question 16

● it occurs if an incident photon has
sufficient energy and may escape
interaction with the electron cloud and
come close enough to the nucleus of the
target atom to come under the influence
of the nuclear force(electrostatic) field
● the interaction between the incident
photon and the nuclear force field
causes the photon to disappear and in
its place appear two electrons, one
positively charged called positron and
one negatively charged(negatron)
● the incident photon must have an energy of at least 1.02 MeV

Answer 16

PAIR PRODUCTION

Question 17

● it occurs with high-energy photons
which escape interaction with
electrons(electron cloud) and the
nuclear electrostatic field and be
absorbed directly by the nucleus
● the nucleus is raised to an excited state
and instantaneously emits a nucleon or
other nuclear fragment
● it occurs with energy above 10 MeV

Answer 17

PHOTODISINTEGRATION

Question 18

1. Coherent Scattering
2. Compton Scattering
3. Photoelectric Effect
4. Pair Production
5. Photodisintegration

Answer 18

• No application(low
  energy)
• Diagnostic radiology
• Diagnostic radiology
• Therapeutic radiology
• Therapeutic radiology