1. Radiation Physics

Question 1

What does the nucleus contain?

Answer 1

Protons (+) and neutrons (neutral).

Question 2

What are electrons?

Answer 2

Negatively charged particles orbiting the nucleus.

Question 3

What is the atomic number (Z)?

Answer 3

Number of protons; determines the element.

Question 4

What is the atomic mass (A)?

Answer 4

Total of protons + neutrons.

Question 5

What is binding energy?

Answer 5

Energy required to remove an electron from its orbital shell.

Question 6

Where are electrons more tightly bound?

Answer 6

Inner shell electrons (e.g., K-shell).

Question 7

What increases binding energy?

Answer 7

Higher atomic number (Z) due to more protons.

Question 8

What is ionization?

Answer 8

Removal of an electron from a neutral atom, creating an ion pair.

Question 9

What is needed for ionization?

Answer 9

External energy exceeding the electron’s binding energy.

Question 10

What is radiation?

Answer 10

Transmission of energy through space or matter.

Question 11

What are the two forms of radiation?

Answer 11

Wave theory and quantum theory.

Question 12

Describe wave theory.

Answer 12

Radiation travels as waves (no mass) at the speed of light.

Question 13

What determines high energy in wave theory?

Answer 13

Short wavelength and high frequency.

Question 14

Describe quantum theory.

Answer 14

Radiation consists of discrete energy packets (photons).

Question 15

What determines high energy in quantum theory?

Answer 15

Short wavelength and high frequency.

Question 16

What is ionizing radiation?

Answer 16

Radiation with enough energy to ionize atoms.

Question 17

Give examples of ionizing radiation.

Answer 17

X-rays, gamma rays, alpha particles, beta particles, neutrons, protons.

Question 18

What is non-ionizing radiation?

Answer 18

Radiation lacking sufficient energy to ionize atoms.

Question 19

What is Linear Energy Transfer (LET)?

Answer 19

Rate of energy loss by radiation as it travels through matter.

Question 20

What is the penetration of high LET radiation?

Answer 20

Less penetration, short range.

Question 21

What is the penetration of low LET radiation?

Answer 21

Greater penetration, longer range.

Question 22

What are X-rays?

Answer 22

Photons with no mass or charge, traveling at the speed of light.

Question 23

What are the properties of X-rays?

Answer 23

Invisible, weightless, neutral, travel in straight lines, ionize matter.

Question 24

What is excitation?

Answer 24

Transfer of energy to an electron, raising it to a higher energy level without ejection.

Question 25

What happens after excitation?

Answer 25

Electron returns to ground state, releasing energy.