Ch. 2 Radiation Concepts Flashcards
What is the definition of Natural Science?
The study of the universe and its contents
It includes both non-living matter (physical sciences) and living matter (biological sciences).
What does Physics deal with?
Matter and energy and their interrelationships
Define Matter.
Anything that occupies space and has mass
What is Mass?
The quantity of matter contained in an object (measured in kg)
What is Weight?
The force that the object exerts under the influence of gravity
Weight is dependent on mass and the gravitational pull.
What is a Substance?
A material that has a definite and constant composition
What are the two types of substances?
- Simple: elements that cannot be broken down
- Mixture: two or more substances mixed together
What are Molecules?
Formed when atoms are bonded
Different degrees of attraction among molecules affect their states (e.g., water, steam, ice).
Define Energy.
The ability to do work
How is Work defined?
Work = force x distance
What is the Law of Conservation of Energy?
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
What is the equation formulated by Albert Einstein regarding energy?
E = mc^2
This equation expresses the equivalence of mass and energy.
What is Mechanical Energy?
The result of machines or physical movement
Mechanical energy includes both potential and kinetic energy.
Define Potential Energy.
The energy an object has due to its position. It is stored energy until converted to another form.
Define Kinetic Energy.
Energy in motion
An example is a boulder rolling down a hill.
What is Chemical Energy?
Energy created from a chemical reaction
Examples include reactions like Mentos in soda or batteries generating electricity.
What is Thermal Energy?
Heat resulting from the motion of atoms or molecules
The faster the atoms move, the more heat they release.
What is Temperature?
The measure of heat thermal energy
What is Electrical Energy?
The movement of electrons through a potential difference/wire
Electricity is the study of resting and moving electrons.
What is nuclear energy?
The energy contained in the nucleus of an atom
Includes both controlled (nuclear power plants) and uncontrolled (nuclear warfare) forms.
What is the electromagnetic spectrum?
A form of energy that results from electric and magnetic disturbances in space or vacuum
Commonly abbreviated as EM Spectrum.
What is the speed of light?
3 x 10^8 meters per second
A fundamental constant in physics.
Define wavelength.
The distance between successive points on a wave, usually measured crest to crest or trough to trough
Measured in Lambda.
What is amplitude in wave theory?
The intensity of the wave, defined by its maximum height
What is frequency?
The number of waves that pass a particular point in a given time frame, measured in Hertz (Hz)
Also known as cycles per second.
What is the relationship between wavelength and frequency?
Wavelength and frequency have an indirect relationship
As one increases, the other decreases.
What is the relationship between frequency and energy?
Frequency and energy have a direct relationship
Higher frequency corresponds to higher energy.
What is the particle theory of electromagnetic radiation?
High frequency electromagnetic radiation can act more like a particle than a wavelength when it interacts with matter
This particle is referred to as a photon or quantum.
What is the period in wave theory?
The time frame for one complete wave cycle
Fill in the blank: The unit of frequency is _______.
Hertz (Hz)
1 Hz equals one cycle per second.
What is an atom?
The smallest unit of an element; what all matter is made of.
What are protons?
Positively charged particles inside the nucleus with atomic weight.
What are neutrons?
Neutral particles inside the nucleus with atomic weight.
What are electrons?
Weightless particles that have a negative charge that constantly move around the nucleus on energy levels.
What is the atomic number (Z#)?
The number of protons in an atom.
What defines a stable atom?
When all atomic particles have the same amount (# of protons = # of electrons).
What is the octet rule?
The atom is most stable when there are no more than 8 electrons in the valence shell.
What is ionization?
The process of adding or removing an electron from its orbital shell.
What is an ion?
A charged atom that has gained or lost an electron.
What is a cation?
A positively charged atom that has lost an electron.
What is an anion?
A negatively charged atom that has gained an electron.
What is atomic weight?
It is equal to the number of protons and neutrons in an atom, measured in amu.
What is an isotope?
Atoms within an element that have the same number of protons but different numbers of neutrons.
The atomic weight for an isotope is different
What is a radioisotope?
An isotope that gives off radioactive decay.
What is radioactive half-life?
The time required for the quantity of a radioactive substance to be reduced by half of its original value.
True or False: After 10 half-lives, a radioisotope is considered inactive.
True.
Fill in the blank: The maximum number of electrons in the K shell is ______.
2
Fill in the blank: The maximum number of electrons in the L shell is ______.
8
Fill in the blank: The maximum number of electrons in the M shell is ______.
18
Fill in the blank: The half-life for I-131 is ______.
3 hours
What is the definition of Electron Binding Energy?
The amount of energy needed to remove an electron from its energy level
Electron Binding Energy is measured in electron volts (eV)
How is Electron Binding Energy (Eb) measured?
In electron volts (eV)
What happens when an electron is removed from an atom?
Ionization has occurred
True or False: The closer the electron is to the nucleus, the lower the Electron Binding Energy.
False
The closer the electron is to the nucleus, the higher the Electron Binding Energy.
Which energy level has a higher Electron Binding Energy, K shell or M shell?
K shell
K shell electrons are closer to the nucleus compared to M shell electrons.
What must an X-ray photon have in order to ionize an atom?
A higher energy (eV) than the Electron Binding Energy of the electron
This means the X-ray photon must possess sufficient energy to overcome the binding energy of the electron.
What does an increase in atomic number generally indicate about Electron Binding Energy?
The higher the atomic number, the higher the Electron Binding Energy
More complex atoms with higher atomic numbers have electrons that are more tightly bound.
What is a radioactive half-life?
The time required for the quantity of radioactivity to be reduced by 1/2 of its original value
