RADT 334 - Unit 1

Energy

The ability to do work or physically influence surroundings based on position, chemical state, or nuclear state.

E=mc^2

Einstein's mass-energy equivalence equation that expresses the relationship between mass (m) and energy (E), indicating that mass can be converted into energy.

Ionizing radiation

Any electromagnetic or particulate radiation that possesses enough energy to remove an electron from an atom, potentially causing significant chemical changes.

mrad

One one-thousandth (1/1000) of a rad, a unit of absorbed radiation dose.

3.1 mSv

The average level of natural environmental radiation exposure measured in millisieverts per year.

Barium platinocyanide

The phosphor with which Wilhelm Conrad Roentgen was experimenting when he discovered x-rays in 1895.

1895

The year in which x-rays were discovered by Wilhelm Conrad Roentgen.

1901

The year Roentgen was awarded the Nobel Prize in Physics for his work on x-rays.

False

True/False: Mass fluctuates with gravitational influence — the correct answer is false.

Electromagnetic radiation examples

Four examples include x-rays, gamma rays, visible light, and radio waves; additional examples include microwaves, infrared radiation, and ultraviolet radiation.

X-ray beam filtration purpose

The purpose of x-ray beam filtration is to remove low-energy x-rays from the beam, which reduces patient exposure.

2.3 mSv

Approximately the amount of the annual radiation dose that is attributable to medical imaging procedures.

ALARA

An acronym for 'As Low As Reasonably Achievable', a principle for minimizing radiation exposure to patients and staff.

Naturally occurring radiation sources

Three sources include cosmic radiation, terrestrial radiation, and internally deposited radionuclides.

Radon gas

A naturally occurring radioactive material that is the leading cause of lung cancer in non-smokers in the United States.

Fundamental units of measurement

Length, mass, and time are the three fundamental units used in scientific measurement.

Derived quantity

A secondary measurement that is obtained through calculations involving one or more of the three base quantities (length, mass, time).

Special quantity

Quantities derived from base quantities that are specifically utilized in specialized scientific fields.

Inertia

According to Newton's first law, inertia is the property of an object to resist changes to its state of motion.

Acceleration

The rate at which an object's velocity changes over time.

Convection

The transfer of thermal energy by the movement of a fluid medium (liquid or gas) from one location to another.

Work

The physical quantity calculated as the force applied to an object multiplied by the distance over which that force is applied.

Velocity

The rate of change of an object's position with respect to time; commonly known as speed.

Force

According to Newton's second law, force is defined as the mass of an object multiplied by its acceleration.

F=ma

The equation representing the relationship between force (F), mass (m), and acceleration (a).

v=d/t

The equation used to calculate velocity (v), where distance (d) is divided by time (t).

a=(vf-vo)/t

The formula for acceleration (a), which is the change in velocity (final velocity minus initial velocity) divided by time.

Action/reaction

This refers to Newton's third law, which states that for every action, there is an equal and opposite reaction.

p=mv

The equation for momentum (p), calculated as mass (m) multiplied by velocity (v).

Common denominator

When adding fractions, it is essential to find a common denominator for the fractions to be combined.

Multiply

To multiply fractions, simply multiply the numerators and the denominators together.

Divide, by

To convert a fraction into a decimal, divide the numerator by the denominator.

Roentgen

A traditional unit of measurement used to calculate radiation intensity in air, denoting exposure.

Rad

The traditional measurement unit for absorbed radiation dose, quantifying energy deposited in a material.

Rem

The traditional measurement unit used to quantify occupational exposure to ionizing radiation.

Curie

A traditional measurement unit that quantifies radioactivity, indicating the activity of a radioactive substance.

C/kg

The SI equivalent of the Roentgen measurement unit for radiation exposure measured in air.

Gray

The SI measurement unit equivalent to the rad, used to indicate the absorbed dose of radiation.

Seivert

The SI equivalent of the rem, a unit that accounts for biological effect in radiation exposure.

Becquerel

The SI equivalent of the curie, a unit used to measure the frequency of radioactive decay.

Photon

The fundamental particle of electromagnetic radiation that carries energy, with no mass and no charge.

Positron

A positively charged beta particle, which is the antimatter counterpart of an electron.

Nucleon

The collective term for protons and neutrons, the particles that reside within an atomic nucleus.

Periodic table

An organized chart representing all known chemical elements arranged by their atomic number, electron configuration, and recurring chemical properties.

Radioactive half-life

The amount of time required for the quantity of a radioactive substance to reduce to half its original value.

K shell

The innermost electron shell of an atom, capable of holding a maximum of two electrons.

Alpha particle

A type of ionizing radiation consisting of two protons and two neutrons; it represents the nucleus of a helium atom.

Beta particle

An electron emitted from the nucleus of a radioactive atom during the process of beta decay.

Isotope

Atoms that share the same atomic number (number of protons) but have different atomic mass numbers (different numbers of neutrons).

Isobar

Atomic nuclei that possess the same atomic mass number but differ in their atomic numbers (number of protons).

Isotone

Atoms that have the same number of neutrons but a different number of protons.

Isomer

Atoms that have identical atomic numbers and atomic mass numbers, existing in different energy states.

Centripetal force

The force that acts on an object moving in a circular path, keeping it in orbit by directing it toward the center of rotation.

Centrifugal force

The perceived force that acts outward on a body moving in a circular path; it is a result of inertia.

Eight

The maximum number of electrons that can occupy the outermost shell of an atom.

Shell number

In the equation 2n² (where n is the shell number), 'n' represents the principal quantum number indicating the energy level.

Neutral

In its normal state, an atom has no net charge, meaning it is electrically neutral with equal numbers of protons and electrons.

Atom

The smallest unit of matter that retains all properties of an element, composed of a nucleus surrounded by electrons.

Atomic number

The number of protons found in the nucleus of an atom, which defines the element.

Atomic mass number

The total number of protons and neutrons present in the nucleus of an atom.

Z

The symbol used to represent the atomic number of an element in chemical notation.

A

The symbol representing the atomic mass number in chemical notation.

Molecule

A group of two or more atoms of different or the same elements bonded together, forming the smallest unit of a compound.

Compound

A substance formed when two or more atoms of different elements chemically bond together, having distinct properties.

Smallest particle of a compound

A molecule is the smallest particle that retains the chemical properties of a compound.

Smallest particle of an element

An atom is the smallest unit of an element, comprising protons, neutrons, and electrons.

Radioactivity

The spontaneous emission of particles and energy from an unstable atomic nucleus as it seeks a more stable configuration.

Periodic table recognition

Dmitri Mendeleev is primarily remembered for creating the periodic table of elements.

Neils Bohr

The scientist who developed the model of the atom as a miniature solar system, where electrons orbit the nucleus.

Fundamental particles within an atom

These include electrons, protons, and neutrons, each playing a crucial role in atomic structure.

Direct relationship of force to mass

There is a direct relationship indicating that force applied to an object is proportional to its mass.

Three methods of thermal energy transfer

The three methods include conduction, convection, and radiation, which describe how heat moves between objects.

Beta particle vs. electron

The primary difference is their origin; beta particles are emitted from the nucleus of radioactive atoms, while electrons are fundamental charge carriers in atoms.

X-ray vs. gamma ray origin

The key difference lies in their origin; x-rays are produced by electronic transitions, while gamma rays result from nuclear decay.

Atomic models

Thomson, Rutherford, Dalton, and Bohr each contributed different perspectives and models on atomic structure and behavior.

Covalent bonds

Chemical bonds formed through the sharing of one or more pairs of electrons between atoms.

Ionic bonds

Chemical bonds formed when electrons are transferred from one atom to another, resulting in charged ions.

True/False: All compounds are molecules

True, as all compounds are made up of molecules containing multiple atoms bonded together.

True/False: All molecules are compounds

False, because some molecules consist of only one type of atom, such as oxygen (O₂), and are not classified as compounds.