Physics chapter challenge questions
Air kerma
1/1000 of a rad, where the rad (radiation absorbed dose) is 100 ergs of energy absorbed per gram of tissue
Liquid hydrogen with a boiling temperature of 77 K is used to cool some superconducting magnets. What is the temperature in degrees Celsius? What is the temperature in Fahrenheit?
13. Temperature in °C = 77K − 273 = −196°C. Temperature in °F = [(−196) 1.8] − 32 = −385°F.
Figure 2-1 shows the following approximate sizes: an atom 10^-10 m; the Earth 10^7m. by how many orders of magnitude do these objects differ?
17 orders of magnitude
Derived quantity
secondary quantities that are derived from a combination of one or more of the three base quantities (volume, density, and velocity)
What are the four special quantities of radiation measurement?
Exposure air kerma Gya (R); absorbed dose Gyt (rad); effective dose Sv (rem); and radioactivity Bq (Ci).
Energy
the ability to do work or physically influence surroundings because of position, chemical state, or nuclear state
what determines the chemical properties of an element
the arrangements of electrons in the outermost shells
1913
the coolidge hot-cathode x-ray tube is introduced
what property of an atom does binding energy describe
the energy required to hold nucleons together as a nucleus (nuclear binding energy) the energy required to maintain electrons in orbit about the nucleus (electron binding energy)
The rutherford atom
the first description of an atom having a nucleus
The coolidge tube
the first heated filament x-ray tube was developed by a physicist , william coolidge in 1913
Alpha particle
the nucleus of the helium atom, has two neutrons and two protons
Describe the process that results in the formation of a negative ion and a positive ion
An x-ray, for instance, interacts with an orbital electron of an atom of tissue. The electron absorbs some energy from the x-ray and is released from the atom. The electron (negative ion) and resulting atom (positive ion) are called an ion pair.
Ionizing radiation
Any electromagnetic or particulate radiation that has sufficient energy to remove an electron from an atom
The acronym ALARA stands for what?
As low as reasonably achievable
The term applied to the chemistry of the body
Biochemistry
What are the three natural sources of whole-body radiation exposure?
Cosmic rays, terrestrial radiation, and internally deposited radionuclides
Chemical compound
New substance that is formed when two or more atoms of different elements combine
who developed the concept of the atom as a miniature solar system
Niels bohr
Can atoms by ionized by changing the number of positive charges
No. positive charges (protons) do not move, they are confined to the nucleus
What percentage of average radiation exposure to a human is attributable to medical x-rays?
Percentage= (39 mrem / 360 mrem) x 100% =11%
What naturally occurring radiation source is responsible for radiation dose to lung tissue
Radon 222, a gas
1895
Roentgen discovers x-rays
1901
Roentgen wins the first nobel prize in physics
Fluoroscopy
The production of continuous x-ray images in real time using a special x-ray imaging system, the fluoroscope, with continuous low mA. The fluoroscope was first demonstrated by Thomas edison in 1898
Acceleration
The rate of change of velocity (speed and/or direction) with time
what are the three units common to the SI and MKS systems?
The three fundamental units of measurements common to the SI and MKS systems are: length (meters, m), mass (kilograms, kg) and time (seconds, s)
10. Complete the following table with relative values. Type of radiation mass energy Charge origin A (alpha symbol?) B B+ Y X
Type Mass Energy Charge Origin 4 amu MeV +2 Nucleus Β 0 amu keV −1 Nucleus β+ 0 amu keV +1 Nucleus Γ 0 MeV 0 Nucleus x 0 keV 0 Electron Shells
What is the velocity of the mobile x-ray imaging system if the hospital elevator travels 20 m to the next floor in 30 s?
Velocity= distance divided by time= 20m/30s = 0.67 m/s
A radiographer has a mass of 58kg. What is her weight on Earth? on the moon?
Weight on Earth= 58 kg x 9.8m/s^2 = 568 N. Weight on the moon= 58kg x 1.6m/s^2 = 93N
Name devices designed to minimize radiation exposure to the patient and the operator
X-ray beam filtration, x-ray beam collimation, protective apparel and barrier, fluoroscopic cumulative timer, and the protective tube housing.
How is x-ray interaction different from that seen in other types of electromagnetic radiation?
X-rays interact at the electron level or nuclear level, ionizing an atom or ejecting a nuclear particle, respectively. Lower-energy electromagnetic radiation interacts with molecules, cells, and larger objects in a way that usually elevate the temperature of the object
Barium platinocyanide
a phosphor that glows when excited with x-rays. This is the phosphor with which Roentgen was experimenting when he discovered x-rays.
the arrangement of the periodic table
an arrangement of all known elements into rows and columns. the rows relate to the number of electron shells present; the columns relate to the number of electrons in the outermost shell
Describe how ion pairs are formed
an ion pair is formed when an electron is removed from an atom by ionizing radiation
photon
any quantum of electromagnetic radiation. It has no mass and no charge.
The average level of natural environmental radiation
approximately 300mrad/yr
Place the following in chronological order. a. Digital fluoroscopy b. American society of radiologic technologists c. Computed technologists d. Radiographic grids e. automatic film processing
d, b, e, c, a
List the fundamental particles within an atom
electrons protons and neutrons
Why doesnt an electron spontaneously fly away from the nucleus of an atom
electrostatic force of attraction, electron binding energy
How does carbon-14 dating determine the age of petrified wood
fixed ^14 C in petrified wood decays, while ^14 C in living wood is replenished
K shell
innermost electron shell
describe the difference between alpha and beta emission
mass and charge on the particle. An alpha particle has four units of mass and two units of positive charge. A beta particle has essentially no mass and one unit of negative charge.
nucleons
neutrons and protons
List five clinical skills required by the ARRT
pg 23 and 24 box 1-2 There is a total of 57 1. Confirm the patient's identity 2. Evaluate the patient's ability to understand and comply with requirements for the requested examination 3. explain and confirm the patient's preparation ( e.g. dietary restrictions, preparatory medications) before performing radiographic and fluroscopic examination 4. Examine radiographic requisition to verify accuracy and completeness of information (e.g., patient history, clinical diagnosis) 5. Sequence imaging procedures to avoid effects if residual contrast material on future examinations.
positron
positively charged beta particle
1907
the snook transformer is developed
How would you define the term radiation
the transfer of energy from one area or medium to another
Radioactive half life
time required to reduce radioactivity to half its original value
What is the purpose of x-ray beam filtration
to keep low-energy x-rays from reaching the patient. Such x-rays do not reach the image receptor. Filtration results in lower patient radiation dose
W is the chemical symbol for what element
tungsten
Describe how weight is different from mass
weight is determined by the force of gravity. Weight changes in value with position in a gravitational field such as that of the Earth or the moon. Mass is constant. It is independent of position and is determined by the object's energy equivalence.
Name four examples of electromagnetic radiation
x-rays, gamma rays, visible light, radio waves (Also microwaves, infrared radiation, ultraviolet radiation)
6. If atoms large enough to have electrons in the T shell existed, what would be the maximum number allowed in that shell?
• 200 electrons
8. From the following list of nuclides, identify sets of isotopes, isobars, and isotones. 60/28 Ni 61/28 Ni 62/28 Ni 59/27 Co 60/27 Co 61/27 Co 58/26 Fe 59/26 Fe 60/26 Fe
• 60Ni - 61Ni - 62Ni = isotopes. • 59Co - 60Co - 61Co = isotopes. • 58Fe - 59Fe - 60Fe = isotopes. • 59Co - 59Fe = isobars. • 60Ni - 60Co - 60Fe = isobars. • 61Ni - 61Co = isobars. • 60Ni - 59Co - 58Fe = isotones. • 61Ni - 60Co - 59Fe = isotones. • 62Ni - 61Co - 60Fe = isotones.
4. Using the data in table 2-1, determine the mass of ^99 Tc in atomic mass units and in kilograms.
• 99 amu; 1.64 x 10^-25 kg
7. How much more tightly bound are K-shell electrons in tungsten than (a) L-shell electrons, (b) M-shell electrons, (c) free electrons? (Refer to Figure 2-9.)
• A. 58 kev • B. 67.2 keV • C. 70 keV
9. 90/38 Sr has a half-life of 29 years. If 10 MBq were present in 1950, approximately how much would remain in 2010?
• Approximately 2.5 MBq
5. Diagram the expected electron configuration of ^40 Ca.
• K= 2 L=8 M=8 N=2
3. How many protons, neutrons, electrons, and nucleons are found in the following 17/8 O 27/13 Al 60/27 Co 226/88 Ra
• O: 8, 9, 8 17 • Al: 13, 14, 13, 27 • Co: 27, 33, 27, 60 • Ra: 88, 138, 88 226
11. For what is Mendeleev remembered?
• Periodic table of the elements
