Physical Properties Of Radiation

Question 1

Explain the concept of ionization

Answer 1

-when ionizing radiation causes an electron to be ejected from an atom

Question 2

Explain the concept of excitation

Answer 2

-when ionizing radiation causes an electron to reach a higher energy state, but it remains with the same atom

Question 3

Determine if the following types of radiations are ionizing or non ionizing 
A) x rays
B) microwaves
C) heat
D) beta particles
E) neutron radiation

Answer 3

A) x-rays: ionizing 
B) microwaves: non ionizing
C) heat: non ionizing
D) beta particles: ionizing
E) neutron radiation: ionizing

Question 4

Which of the following is the best description of radiation?
A) acts as a particle
B) acts as a wave
C) may act as either a particle or a wave

Answer 4

C! May act as either a particle or a wave

Question 5

What is the traditional unit of occupational exposure?

Answer 5

Rem!

Question 6

What is the international unit of occupational exposure?

Answer 6

Sievert!

Question 7

Define the term wavelength

Answer 7

• Distance between any two successive points on a wave
• measured crest-crest or trough-trough
• represented by greek letter lambda

Question 8

What unit is used to measure wavelength?

Answer 8

The meter is used to measure wavelength

Question 9

Define the term frequency

Answer 9

The number of waves that pass a particular point during a given time frame, or the number of cycles per second

Question 10

What unit is used to measure frequency?

Answer 10

Frequency is measured in hertz or cycles per second

Question 11

What is hertz equal to?

Answer 11

1 hertz= 1 cycle/second

Question 12

Explain the relationship between frequency, wavelength and velocity of a wave

Answer 12

• frequency and wavelength are inversely proportional (the wavelength decreases, frequency increases and vice versa)
• product of frequency and wavelength of electromagnetic radiation always equals the velocity of the speed of light (3X10 to the 8 m/s)

Question 13

Describe the wavelength of x-radiation

Answer 13

-x-radiation has a short wavelength compared to lower-energy electromagnetic radiation like visible light

Question 14

How does radiation differ within the electromagnetic spectrum?

Answer 14

• as the energy level rises, wavelength decreases and frequency increases
• radiation varies depending on the energy level
• low energy levels are at the bottom end of the spectrum with radio waves and microwaves
• visible light is at the centre of the spectrum
• high energy levels contain gamma and x-rays

Question 15

What is the speed of light?

Answer 15

3x10 to the 8 m/s (186,000 miles per second)

Question 16

What is the wave equation?

Answer 16

Velocity= frequency x wavelength

Question 17

Which source of radiation gives the largest radiation exposure to the population?

Answer 17

Natural background radiation gives the largest radiation dose to the population more than medical and man-made sources combined

Question 18

Which source gives its radiation exposure to the lungs only?

Answer 18

Radon gas exposure occurs only to the lungs

Question 19

Where does cosmic radiation come from?

Answer 19

From the sun, space and stars

Question 20

Does cosmic radiation increase or decrease at higher altitudes?

Answer 20

It increases at higher altitudes

Question 21

What man-made source gives the highest population dose?

Answer 21

Highest population dose from man-made sources is from medical procedures that involve radiation

Question 22

1) of 14 properties of x-rays

Answer 22

X-rays are invisible, cannot be seen, felt, smelt or heard

Question 23

2) of 14 properties of x-rays

Answer 23

X-rays are electrically neutral

• neither + or - charge
• cannot be accelerated
• magnets or electrical fields cannot change the photons direction

Question 24

3) of 14 properties of x-rays

Answer 24

X-rays have no mass

• create no resistance to being put into motion
• cannot produce force

Question 25

4) of 14 properties of x-rays

Answer 25

X-rays travel at the speed of light in a vacuum | -moving at a constant velocity of 3x10 to the 8 m/s

Question 26

5) of 14 properties of x-rays

Answer 26

X-rays cannot be optically focused | -optical lenses have no ability to focus or refract photons

Question 27

6) of 14 properties of x-rays

Answer 27

X-rays form a poly energetic or heterogenous beam - x-ray beam used in diagnostic radiography is composed of photons that have many different energies - maximum energy of a photon is expressed by the kilovoltage peak (kVp) set on the control panel by the radiographer

Question 28

7) of 14 properties of x-rays

Answer 28

X-rays can be produced in a range of energies - useful for different purposes - medically useful diagnostic range is from 30-150 kVp

Question 29

8) of 14 properties of x-rays

Answer 29

X-rays travel in straight lines - each individual photon travels in a straight line - forms a divergent beam

Question 30

9) of 14 properties of x-rays

Answer 30

X-rays can cause some substances to fluoresce - when x-rays strike some phosphors producing light - phosphors are used in image intensifiers in fluoroscopy

Question 31

10) of 14 properties of x-rays

Answer 31

X-rays cause chemical changes to occur in radiographic and photographic film -capable of creating images or fogging any type of photographic film

Question 32

11) of 14 properties of x-rays

Answer 32

X-rays can penetrate the human body - passes through the anatomy based on the beam energy - determined by the composition, thickness of the anatomy exposed

Question 33

12) of 14 properties of x-rays

Answer 33

X-rays can be absorbed or scattered by the anatomy -depends on the energy of the individual x-ray photon -photons may be: 🔹absorbed- in the anatomy (dose) 🔹scattered- moving in another direction 🔹transmitted- to the IR

Question 34

13) of 14 properties of x-rays

Answer 34

X-rays can produce secondary radiation -x-rays introduction causes a specific type of interaction with matter producing: 🔹secondary photon 🔹characteristic photon

Question 35

14) of 14 properties of x-rays

Answer 35

X-rays can cause chemical and biologic damage to living tissue - excitation and ionization of atoms comprises cells - damage to cells can occur

Question 36

Both light and x-rays are electromagnetic radiation but can x-rays be reflected like light?

Answer 36

- no, photons have no mass or charge - photons travel in straight lines - travel through matter instead of being reflected - important property for creating diagnostic images

Question 37

Can x-radiation remove and electron from its orbit?

Answer 37

Yes, photons can ionize matter, so they are capable of removing an electron from its orbit

Question 38

At what speed does x-radiation travel?

Answer 38

Ionizing radiation travels at the speed of light in a vacuum (3x10 to the 8 m/s)