Radtech

• Matter


  Anything that occupies space and has mass. It is the material substance of which physical objects are composed. Matter is composed of atoms
• Energy


  Energy can exist in several forms, just like matter. Energy is the ability to do work. Energy is measured in joules (J) when using the International System. Energy is measured in electron volt (eV) when used in radiology. Forms of energy can be transformed from one type to another. Energy and Matter (Mass) can be interchangeable. Energy that is emitted and transferred through space is called radiation
• Standard Units of Measurement

  • Base Quantities: Mass, Length, Time
  • Derived Quantities: Volume, Mass Density, Velocity, Acceleration
  • Special Quantities: Exposure, Dose, Effective Dose, Radioactivity
• Base Quantities

  • Length: Measured in Meters
  • Mass: Measured in Kilograms
  • Time: Measured in Seconds
• Greek Atom: Matter is composed of four substances - earth, water, air, and fire. All matter could be described as combinations of these four basic substances in various proportions, modified by four basic essences - wet, dry, hot, and cold
• Forms of Energy

  • Potential Energy - The ability to do work by virtue of position
  • Kinetic Energy - The energy of motion possessed by all matter in motion
  • Chemical Energy - Energy released by a chemical reaction
  • Electrical Energy - Represents the work that can be done when an electron moves through an electric potential difference (voltage)
  • Thermal Energy - The energy of motion at the molecular level, closely related to temperature
  • Nuclear Energy - The energy contained within the nucleus of an atom
  • Electromagnetic Energy - Least familiar form of energy, most important in radiology, used in x-ray imaging, includes x-rays and gamma rays
• Mass and Weight

  Mass is the quantity of matter as described by its energy equivalence. Mass is measured in kilograms. Mass will remain unchanged regardless of its state (solid, liquid, gas). Weight is the force exerted on a body under the influence of gravity. The mass of an object remains the same whether it is on earth or on the moon, but its weight will change due to the force of gravity
• Units

  A unit is one part of a measurement. It is the measurement of a quantity. The magnitude is the numerical value. Example: The distance of a radiation source to the imaging plate is 100 cm. 100 is the magnitude. Centimeter is the unit
• Dalton Atom: John Dalton showed that the eleme
• Atom


  The smallest particle that has the properties of an element. It is the building block of the radiographer’s understanding of the interaction between ionizing radiation and matter. The term “atom” came from the Greek word “atomos” which means indivisible. Atoms are electrically neutral in their normal state and consist of protons, neutrons, and electrons
• Rutherford Atom


  • Disproved Thomson’s atomic model. Discovered the nucleus of the atom. Proposed the Nuclear Model of the Atom wherein electrons revolve around the nucleus in fixed paths called orbits
• Atom


  The term “atom” came from the Greek word “atomos” which means indivisible. Atoms are electrically neutral in their normal state and consist of protons, neutrons, and electrons
• Dmitri Mendeleev


  • If the elements were arranged in order of increasing atomic mass, a periodic repetition of similar chemical properties occurred. His work resulted in the first periodic table of the elements
• Greek Atom


  • Matter is composed of four substances: earth, water, air, and fire. All matter could be described as combinations of these four basic substances in various proportions, modified by four basic essences: wet, dry, hot, and cold
• Fundamental Particles


  • The fundamental particles of the atom consist of the nucleons (protons and neutrons) and electrons. Protons and Neutrons are composed of quarks that are held together by gluons. The number of Protons determines the type of chemical element
• Dalton Atom


  • An element was composed of identical atoms that reacted the same way chemically. Dalton’s atomic model suggested that physical combination of one type of atom with another was visualized as being an eye-and-hook affair
• Components of an atom

  • Protons
  • Neutrons
  • Electrons
• Thomson Atom


  • Electrons were an integral part of all atoms. His atomic model was based on a plum pudding in which the plums represented negative electric charges and the pudding was a shapeless mass of uniform positive electrification
• Fundamental Particles


  • Atomic mass unit is used to express the mass of extremely small atomic particles for precision and convenience. One amu is equal to one twelfth the mass of a Carbon-12 atom. Atomic mass number is used to express the mass of atomic particles if precision is not necessary
• Bohr Atom

  • Improved Rutherford’s model of the atom. Introduced his model in the form of a miniature solar system in which electrons revolved about the nucleus in prescribed orbits
• Beta particles have lower ionizing power than alpha particles but can penetrate thin materials like aluminum foil.
• Radiation chemistry is concerned with the study of these radiation-induced processes.