Midterm Study Guide

Question 1

Physics involves what two things?

Answer 1

Matter, energy

Question 2

This part of physics occupies space

Answer 2

Matter

Question 3

Energy has the ability to do _____

Answer 3

Work

Question 4

List the three atomic parts:

Answer 4

1. Protons (+)
2. Neutrons (neutral)
3. Electrons (-)

Question 5

The # of protons = what?

Answer 5

The atomic number

Question 6

1 proton (#1 on table of elements)

Answer 6

Hydrogen

Question 7

The ___ number = protons + neutrons

Answer 7

Mass

Question 8

When an element is the same (same number of protons), but the mass number is different (different # of neutrons) it is called an ______

Answer 8

Isotope

Question 9

When you change the number of ELECTRONS this is called ____

Answer 9

Ionization

Question 10

More electrons = (__) ion, less electrons = (__) ion

Answer 10

-, +

Question 11

What do the letters stand for? E=MC^2

Answer 11

Energy = Mass(Constant^2)

Question 12

Constant is what?

Answer 12

Speed of light

Question 13

There are many forms of energy. This type is created by movement (windmill)

Answer 13

Mechanical

Question 14

This type of energy is “stored energy”, as is pressure loading a spring

Answer 14

Potential

Question 15

Energy in motion (such as a roller coaster) is known as _____

Answer 15

Kinetic

Question 16

A battery can be categorized as ___ energy

Answer 16

Chemical

Question 17

___ energy is movement of electrons (such as power wires)

Answer 17

Electrical

Question 18

____ energy is “in the tight bonds of atoms”. Ex: bomb

Answer 18

Nuclear

Question 19

Energy that holds electrons in their orbits around the nucleus

Answer 19

Binding energy

Question 20

Energy that moving electrons possess in their orbit

Answer 20

Centripetal energy

Question 21

The closer the nucleus, the ___ the binding energy and the ___ the centripetal energy

Answer 21

Greater, lower

Question 22

The three components of the electromagnetic spectrum:

Answer 22

1. Wavelength
2. Frequency
3. Energy

Question 23

____ is measured as the distance from crest to crest on a “wavy” line

Answer 23

Wavelength

Question 24

____ = frequency x wavelength

Answer 24

Velocity

Question 25

Frequency and wavelength are ____ proportional. One gets larger the other gets smaller

Answer 25

Inversely

Question 26

Frequency and Energy are ____ proportional. They both get larger or smaller together

Answer 26

Directly

Question 27

Frequency is measured in ___

Answer 27

Hertz (Hz)

Question 28

The discoverer or developer of X-Rays

Answer 28

Wilhelm Roentgen (1895)

Question 29

These are electrically neutral, travel straight and at the speed of light, can cause ionization in matter, cause fluorescence (light from crystals), cannot be focused by a lens, produce changes in matter, and produce secondary/scatter radiation

Answer 29

X-rays (these are their properties)

Question 30

In general, the # of something per area is called ____

Answer 30

Density

Question 31

When radiation can go THROUGH the object, that object is considered radioLUCENT. This results in an area of ____ radiographic density (black area on film)

Answer 31

High

Question 32

An object that can stop the radiation from going through it is considered radioopaque. This results in an area of ___ radiographic density (clear/white on film)

Answer 32

Low

Question 33

The negative end of the X-ray tube is called _____, the positive end is called ____

Answer 33

Cathode, anode

Question 34

The ____ on the cathode end of the tube heats up to 2,200 degrees to release electrons

Answer 34

Filament

Question 35

The release of electrons from the filament is called ___ emission

Answer 35

Thermionic

Question 36

This is a rotating part of the X-Ray Tube, made of tungsten due to it’s high melting point. This is where the “X-rays” are made

Answer 36

Anode

Question 37

____ are created by getting the electrons up to 1/2 the speed of light and smashing them into the anode

Answer 37

X-rays

Question 38

The ___ motor rotates the anode at 3,600 RPM

Answer 38

Stator

Question 39

Why do they have the anode rotate?

Answer 39

Dissipates heat

Question 40

Current is measured in ____

Answer 40

Amperes (amps)

Question 41

mA stands for?

Answer 41

Milliamperes (milliamps)

Question 42

This is a measure of the current through the filament. It controls the NUMBER of electrons that are boiled off

Answer 42

Milliamps (mA)

Question 43

Force is measured in ___

Answer 43

Voltage (V)

Question 44

This controls the SPEED of electrons and energy of the x-ray

Answer 44

Force (kV)

Question 45

Peak force, AKA ____

Answer 45

kVp

Question 46

When we set the voltage on an x-ray machine we call it ____

Answer 46

Kilovolts peak (kVp)

Question 47

What are the 3 settings to get an image via x-ray?

Answer 47

1. mA (current) 2. kVp (peak force) 3. Time

Question 48

The Big Formula?

Answer 48

mA x Time(S) =mAS

Question 49

If you increase the mAS you ____ the density

Answer 49

Increase

Question 50

So, doubling the mAS would ___ the radiographic density

Answer 50

Double

Question 51

The ____ interaction is when electrons interact with the nucleus, the path is changed and energy is given off in the form of an x-ray

Answer 51

Bremsstrahlung

Question 52

Tungsten is #___ on the table of elements

Answer 52

74

Question 53

When vibration of the electrons without removing the electron from it’s shell occurs, ____ is the result

Answer 53

Heat

Question 54

Heat is __% of the electron interactions at the anode

Answer 54

99%

Question 55

Bremsstrahlung is __-__% of the remaining 1% of electron interactions at the anode (heat is 99%)

Answer 55

80-90%

Question 56

This is equal to mA x kVp x S(time)

Answer 56

Heat units

Question 57

The higher the kVp, the ____ the radiographic density (if mA and time stay the same)

Answer 57

Higher

Question 58

If you increase the kVp by __% you will have the same effect as doubling the density.

Answer 58

15%

Question 59

Rule of thumb for 15% kVp increase: an increase in kVp by __ in the 60-90 range will double the radiographic density

Answer 59

10

Question 60

A variation of the intensity of the x-ray beam due to the configuration of the anode is called the ____ effect

Answer 60

Anode heel

Question 61

An x-ray photon with energy > or = to 10 MeV (10,000 kV) strikes the nucleus of an atom. The energy of the photon is absorbed and a nuclear particle is ejected. Not seen in diagnostic radiology because of remarkably high levels of energy that are necessary for it. This is called ____

Answer 61

Photodisintegration

Question 62

____ is an interaction of x-rays with matter at 1,000 kV. The photon hits the nucleus and 2 particles are produced, one negative electron and one positive electron (positron).

Answer 62

Pair production

Question 63

Coherent/classical scattering of x-rays is below __ kV w/no change in energy, just direction.

Answer 63

5

Question 64

____ scattering removes and electron (e-) and changes direction w/most of it’s energy

Answer 64

Compton’s

Question 65

The ___ effect occurs when there is absorption of the energy and an electron (e-) is ejected. The X-ray has been stopped.

Answer 65

Photoelectric

Question 66

3 factors of? 1. X-ray photon must have more energy than the electron to knock it out of it’s shell. 2. The closer the energies of the photon and electron the more likely the effect is to happen 3. Electrons that are more tightly bound will increase the chances that this effect occurs (more electrons = more likely to occur)

Answer 66

Photoelectric effect

Question 67

Increased kVp = _____ scatter

Answer 67

Increased (less likely that photoelectric effect will occur)

Question 68

If you go up 15% kVp (to double the density), you would have to do what to your mAS to keep the radiographic density the same as it was on the first image?

Answer 68

Cut it in half