Ch. 1

Question 1

What is Heat Energy?

Answer 1

Heat energy results from molecules in motion

Question 2

Example of Kinetic Energy?

Answer 2

When a ball is dropped from the top of a cliff

conversion of PE to KE

Question 3

How many eV’s is equal to 1 keV?

Answer 3

1,000 eV

Question 4

Law of Conservation of Energy

Answer 4

States thats energy can neither be created nor destroyed.

Question 5

Power

Answer 5

• The rate at which work is done

- Power is measured in joules/sec (J/s) which is a watt (W)

Question 6

Isotope

Answer 6

Atoms that have the same number of protons but a different number of neutrons

Question 7

What is ionization

Answer 7

the process by which an atom or a molecule acquires a negative or positive charge by gaining or losing electrons to form ions

Question 8

Difference between a Gamma Ray and an X-ray

Answer 8

Their origin
-Gamma rays: decomposition of nucleotides
and result from radioactive decay
-X-rays: are produced when electrons strike a target or when electrons are rearranged in an atom (ionizing radiation)

Question 9

Discovery of X-rays

Answer 9

1895 – Wilhelm Conrad Röntgen

- Identified use of barium platinocyanide

Question 10

Particulate Radiation

Answer 10

• Involve Alpha and Beta particles
• ionizing
• High engery electrons
• protons
• neutrons

Question 11

Alpha Particles

Answer 11

-Have a high energy helium nucleus
 (2 p, 2 n)
-Large amount of mass & charge
-Can travel 5 cm in air
-In tissue, can only travel 0.1 mm b/c tissue has a higher density

Question 12

Beta Particles

Answer 12

• Electrons from radioactive decaying material
• Little mass and charge
• Can travel 10-100 cm in air
• In tissue, can travel up to 10 mm
• Can be negative or positive

Question 13

Ionizing Electromagnetic Radiation

Answer 13

X-rays and Gamma Rays

Question 14

Photon

Answer 14

smallest quantity of any type of electromagnetic wave

Question 15

Bundle of Energy

Answer 15

termed as a photon or quantum

Question 16

Air Kerma

Answer 16

Kinetic energy per unit mass of air
- used to describe: tube output, input to IR’s
-Air Kerma of 1 cGy = 1 rad (equivalent to 1 R of
exposure)
-Air kerma is an easily measured and comparable factor used for entrance skin exposure

Question 17

Absorbed Dose

Answer 17

measures amount of energy absorbed (in whatever tissue we are talking about)

• conventional unit: 1 rad = 100 ergs/gm
• SI unit: 1 Gy = 100 rad

Question 18

If given Gy unit…

Answer 18

multiply by 100 to get rad

Question 19

If given rad…

Answer 19

multiply by 0.01 to get a Gy

Question 20

Who invented Fluroscopy

Answer 20

Thomas Edison

Question 21

What is the dose limit for radiation workers per yr.

Answer 21

5 rem total amount of effective dose of radiation per yr

Question 22

Exposure

Answer 22

of ionizations in a given quantity of air

• how much radiation is coming from the tube and to the patient
• Units: Roentgen (R)

Question 23

Equivalent Dose

Answer 23

(Ht) product of absorbed dose & radiation weighting

Question 24

Kerma

Answer 24

Kinetic Energy Released in Mass

• at diagnostic energies
• Kerma equivalent to dose
• Unit Gray

Question 25

Effective Dose

Answer 25

(E) sum of equivalent doses of specific tissues

Question 26

Natural Resources of Radiation

Answer 26

- Sun and stars (cosmic rays) - Terrestrial radiation - Radionuclides: part of human metabolism - potassium-40

Question 27

Manmade Resources of Radiation

Answer 27

- Medical x-rays: largeste source of manmade radiation - Nuclear power plants - industrial resources - smoke detecors - televisions

Question 28

Name a few X-ray properties

Answer 28

- Electrically neutral - Release heat when passing through matter - Travel in straight lines - Travel at the speed of light - Can ionize matter