1. Fundamentals of Radiation and Radioactivity - 10%

Question 1

Define radioactivity.

Answer 1

Emission of radiation from unstable atom.

Question 2

Identify physical aspects of radioactivity.

Answer 2

Ray 1 - Photoelectric Effect: travel @ speed of light; ray passes into steel & collides “head on” w/ an orbital electron from atom
Ray 2 - Compton Effect: 2nd ray passes into steel & also collides w/ an electron from atom
Pair Production: initial photon energy is very high; as photon energy approaches nucleus of atom - changed into an electron -positron pair

Question 3

Identify the types of radiation.

Answer 3

1. Alpha (+) - Large, slow moving particles
2. Beta (-) - Very light particle w/ high velocity
3. Neutron - Particle radiation w/ same mass as proton but no electrical charge
4. X & Gamma - Electromagnetic w/ very high energy

Question 4

Identify measurement of activity.

Answer 4

Ci, Bq (SI Unit)

Question 5

Identify characteristics of scatter radiation.

Answer 5

Radiation that has been deflected from its path by impact with matter.

Question 6

Identify the concept of electromagnetic radiation.

Answer 6

Shorter wavelength, higher frequency.

Question 7

Identify the half-life and relative energy levels of various isotopes used in radiography.

Answer 7

Iridium 192 - 74 days
Cobalt 60 - 5 yrs
Cesium 137 - 30 yrs

Question 8

High-risk sources of radiation.

Answer 8

Cobalt 60, Iridium 192, Cesium 137

Question 9

Hazards and effects of radiation.

Answer 9

Acute - within mins/days/weeks
Chronic - years or generations later
Somatic - rad injury to person but not reproductive cells
Genetic - exposure that results in chromosome damage

Question 10

Identify acute and chronic effects of radiation on humans.

Answer 10

Acute - burns to hands

Chronic - cancer, genetic defects