Ch. 2 Radiation Concepts

Question 1

What is the definition of Natural Science?

Answer 1

The study of the universe and its contents

It includes both non-living matter (physical sciences) and living matter (biological sciences).

Question 2

What does Physics deal with?

Answer 2

Matter and energy and their interrelationships

Question 3

Define Matter.

Answer 3

Anything that occupies space and has mass

Question 4

What is Mass?

Answer 4

The quantity of matter contained in an object (measured in kg)

Question 5

What is Weight?

Answer 5

The force that the object exerts under the influence of gravity

Weight is dependent on mass and the gravitational pull.

Question 6

What is a Substance?

Answer 6

A material that has a definite and constant composition

Question 7

What are the two types of substances?

Answer 7

• Simple: elements that cannot be broken down
• Mixture: two or more substances mixed together

Question 8

What are Molecules?

Answer 8

Formed when atoms are bonded

Different degrees of attraction among molecules affect their states (e.g., water, steam, ice).

Question 9

Define Energy.

Answer 9

The ability to do work

Question 10

How is Work defined?

Answer 10

Work = force x distance

Question 11

What is the Law of Conservation of Energy?

Answer 11

The sum total of all matter and energy cannot be created or destroyed but can be converted from one form into another

E=mc^2

Question 12

What is the equation formulated by Albert Einstein regarding energy?

Answer 12

E = mc^2

This equation expresses the equivalence of mass and energy.

Question 13

What is Mechanical Energy?

Answer 13

The result of machines or physical movement

Mechanical energy includes both potential and kinetic energy.

Question 14

Define Potential Energy.

Answer 14

The energy an object has due to its position. It is stored energy until converted to another form.

Question 15

Define Kinetic Energy.

Answer 15

Energy in motion

An example is a boulder rolling down a hill.

Question 16

What is Chemical Energy?

Answer 16

Energy created from a chemical reaction

Examples include reactions like Mentos in soda or batteries generating electricity.

Question 17

What is Thermal Energy?

Answer 17

Heat resulting from the motion of atoms or molecules

The faster the atoms move, the more heat they release.

Question 18

What is Temperature?

Answer 18

The measure of heat thermal energy

Question 19

What is Electrical Energy?

Answer 19

The movement of electrons through a potential difference/wire

Electricity is the study of resting and moving electrons.

Question 20

What is nuclear energy?

Answer 20

The energy contained in the nucleus of an atom

Includes both controlled (nuclear power plants) and uncontrolled (nuclear warfare) forms.

Question 21

What is the electromagnetic spectrum?

Answer 21

A form of energy that results from electric and magnetic disturbances in space or vacuum

Commonly abbreviated as EM Spectrum.

Question 22

What is the speed of light?

Answer 22

3 x 10^8 meters per second

A fundamental constant in physics.

Question 23

Define wavelength.

Answer 23

The distance between successive points on a wave, usually measured crest to crest or trough to trough

Measured in Lambda.

Question 24

What is amplitude in wave theory?

Answer 24

The intensity of the wave, defined by its maximum height

Question 25

What is frequency?

Answer 25

The number of waves that pass a particular point in a given time frame, measured in Hertz (Hz) ## Footnote Also known as cycles per second.

Question 26

What is the relationship between wavelength and frequency?

Answer 26

Wavelength and frequency have an indirect relationship ## Footnote As one increases, the other decreases.

Question 27

What is the relationship between frequency and energy?

Answer 27

Frequency and energy have a direct relationship ## Footnote Higher frequency corresponds to higher energy.

Question 28

What is the particle theory of electromagnetic radiation?

Answer 28

High frequency electromagnetic radiation can act more like a particle than a wavelength when it interacts with matter ## Footnote This particle is referred to as a photon or quantum.

Question 29

What is the period in wave theory?

Answer 29

The time frame for one complete wave cycle

Question 30

Fill in the blank: The unit of frequency is _______.

Answer 30

Hertz (Hz) ## Footnote 1 Hz equals one cycle per second.

Question 31

What is an atom?

Answer 31

The smallest unit of an element; what all matter is made of.

Question 32

What are protons?

Answer 32

Positively charged particles inside the nucleus with atomic weight.

Question 33

What are neutrons?

Answer 33

Neutral particles inside the nucleus with atomic weight.

Question 34

What are electrons?

Answer 34

Weightless particles that have a negative charge that constantly move around the nucleus on energy levels.

Question 35

What is the atomic number (Z#)?

Answer 35

The number of protons in an atom.

Question 36

What defines a stable atom?

Answer 36

When all atomic particles have the same amount (# of protons = # of electrons).

Question 37

What is the octet rule?

Answer 37

The atom is most stable when there are no more than 8 electrons in the valence shell.

Question 38

What is ionization?

Answer 38

The process of adding or removing an electron from its orbital shell.

Question 39

What is an ion?

Answer 39

A charged atom that has gained or lost an electron.

Question 40

What is a cation?

Answer 40

A positively charged atom that has lost an electron.

Question 41

What is an anion?

Answer 41

A negatively charged atom that has gained an electron.

Question 42

What is atomic weight?

Answer 42

It is equal to the number of protons and neutrons in an atom, measured in amu.

Question 43

What is an isotope?

Answer 43

Atoms within an element that have the same number of protons but different numbers of neutrons. The atomic weight for an isotope is different

Question 44

What is a radioisotope?

Answer 44

An isotope that gives off radioactive decay.

Question 45

What is radioactive half-life?

Answer 45

The time required for the quantity of a radioactive substance to be reduced by half of its original value.

Question 46

True or False: After 10 half-lives, a radioisotope is considered inactive.

Answer 46

True.

Question 47

Fill in the blank: The maximum number of electrons in the K shell is ______.

Answer 47

2

Question 48

Fill in the blank: The maximum number of electrons in the L shell is ______.

Answer 48

8

Question 49

Fill in the blank: The maximum number of electrons in the M shell is ______.

Answer 49

18

Question 50

Fill in the blank: The half-life for I-131 is ______.

Answer 50

3 hours

Question 51

What is the definition of Electron Binding Energy?

Answer 51

The amount of energy needed to remove an electron from its energy level ## Footnote Electron Binding Energy is measured in electron volts (eV)

Question 52

How is Electron Binding Energy (Eb) measured?

Answer 52

In electron volts (eV)

Question 53

What happens when an electron is removed from an atom?

Answer 53

Ionization has occurred

Question 54

True or False: The closer the electron is to the nucleus, the lower the Electron Binding Energy.

Answer 54

False ## Footnote The closer the electron is to the nucleus, the higher the Electron Binding Energy.

Question 55

Which energy level has a higher Electron Binding Energy, K shell or M shell?

Answer 55

K shell ## Footnote K shell electrons are closer to the nucleus compared to M shell electrons.

Question 56

What must an X-ray photon have in order to ionize an atom?

Answer 56

A higher energy (eV) than the Electron Binding Energy of the electron ## Footnote This means the X-ray photon must possess sufficient energy to overcome the binding energy of the electron.

Question 57

What does an increase in atomic number generally indicate about Electron Binding Energy?

Answer 57

The higher the atomic number, the higher the Electron Binding Energy ## Footnote More complex atoms with higher atomic numbers have electrons that are more tightly bound.

Question 58

What is a radioactive half-life?

Answer 58

The time required for the quantity of radioactivity to be reduced by 1/2 of its original value