Ionizing radiation

Question 1

Matter:

Answer 1

Anything that has mass
and occupies a space

Question 2

The — is the basic unit of all
matter

Answer 2

atom

Question 3

Nucleus:

Answer 3

Protons + Neutrons

Question 4

Atomic number (Z)
(3)
ex

Answer 4

▪ Number of protons
▪ Same as #of electrons in a
neutral atom
▪ Determines the identity of the
atom
▪ Example: Ca has 20 protons
(Atomic number is 20)

Question 5

Atomic mass (A)
(1)

Answer 5

▪ Number of protons + neutrons

Question 6

tugesten

Answer 6

184, 74

Question 7

BINDING ENERGY

Answer 7

• The amount of energy
required to remove an
electron from its shell.

Question 8

BINDING ENERGY
measured in

Answer 8

Measured in electron Volts
(eV)

Question 9

Within a given atom, inner
shells electrons are

Answer 9

more
tightly bound (K>L>M, etc)

Question 10

The electron binding energy is
related to the atomic number.

Answer 10

High Z: more protons → Electrons
are more tightly bound.

Question 11

Electron = protons →

Answer 11

Neutral atom

Question 12

Ionization

Answer 12

▪ Process of forming a positive and negative ion by removal of an electronfrom an neutral atom

Question 13

If a neutral atom loses an electron becomes a — ion and the free electron becomes a — ion.

Answer 13

positive
negative

Question 14

To ionize an atom, we need sufficient external energy to overcome the

Answer 14

electrostatic forces and free the electron.

Question 15

Radiation

Answer 15

▪ Is the transmission of energy through space (vacuum) and matter

Question 16

Radiation
It may occur in two forms:

Answer 16

wave theory or quantum (particles) theory

Question 17

Wave theory:

Answer 17

explains the propagation of radiation

Question 18

Quantum theory:

Answer 18

explains the interaction of radiation withmatter.

Question 19

Waves Theory: Electromag. Radiation

Answer 19

▪ Propagation of radiation in form of waves (no mass) traveling at the
speed of light

Question 20

Waves Theory: Electromag. Radiation
▪ Why electromagnetic?

Answer 20

Movement of energy through space as a
combination of electric and magnetic fields.

Question 21

Wavelength:

Answer 21

Distance between two successive crests

Question 22

Frequency:

Answer 22

Number of wavelength passing a particular point in time

Question 23

High energy radiation:

Answer 23

High frequency, short wavelength

Question 24

Low energy radiation:

Answer 24

Low frequency, long wavelength

Question 25

Non-Ionizing

Answer 25

▪ Does not have sufficient energy to
eject an electron from the shells

Question 26

Ionizing

Answer 26

▪ Have sufficient energy to eject
an electron from the shells

Question 27

Quantum theory:

Answer 27

explains the interaction of radiation with matter.

Question 28

Quantum theory:
▪ Considers radiation as small discrete bundles of energy called —.

Answer 28

photons

Question 29

▪ Each photon has (3)

Answer 29

energy (eV), mass and travels in straight lines at the speedof light.

Question 30

particles are — charged (except neutrons and x-rays)

Answer 30

Electrically

Question 31

▪ Energy: Directly proportional to —, inversely proportional to
—.

Answer 31

frequency
wavelength

Question 32

High frequency means short wavelength →

Answer 32

High energy

Question 33

Low frequency means long wavelength →

Answer 33

Low energy

Question 34

Ionizing rate: Linear energy transfer (LET)

Answer 34

▪ Rate of loss of energy from a particle as it moves through matter

Question 35

Ionizing rate: Linear energy transfer (LET)
▪ Depends on (3)

Answer 35

velocity, charge and size.
– Lower velocity, higher charge and bigger size →Greater LET
– Higher LET: Less penetration because they lose their energy after short distances

Question 36

What are X-rays?

Answer 36

▪ They are weightless* packages of pure energy (photons) without an
electrical charge which travel in waves with a specific frequency and
wavelength at the speed of light (3x108 m/sec) and are able to ionize
matter.

Question 37

Properties of X-rays
(7)

Answer 37

1. Invisible, weightless*, no electric charge
2. Travels in straight lines.
   X-ray beam diverges over distance.
3. Travel at the speed of light
4. Highly penetrating (short wavelengths)
   0.01 nm to 0.1 nm
5. Differentially absorbed by matter
6. Can ionize matter
7. Produce biological changes

Question 38

Excitation
(2)

Answer 38

▪ When the transferred energy is not sufficient to overcome binding
energy, e- is NOT ejected
▪ Receiving e- is raised to higher energy level within the orbit.
Instantaneously gives up this excess energy and returns to ground
level