Radiation physics Flashcards
What is matter?
Anything that occupies space and has mass
What is an atom?
The fundamental unit of matter, all matter is composed of atoms
What is the atomic structure?
An atom has a central nucleus orbiting electrons. The identity is determined by the composition of the nucleus and the arrangement of orbiting electrons
What is the nucleus composed of?
Protons and neutrons. Protons have a positive electrical charge, neutrons carry no electrical charge. Most of the atom is empty space
Is the nucleus affected by x-rays?
No, only the orbiting electrons. It is the outer shell of electrons that may be disrupted during dental radiography.
What is an electron?
Tiny, negatively charged particles. Smaller than protons. Travel around the nucleus in orbits or shells. The shell located closest to the nucleus has the highest energy level
What is the binding energy of an electron and how is it determined?
Electrons are maintained in their orbits by the electrostatic force between the positive nucleus and the negative electrons. The binding energy of an electron is determined by the distance between the nucleus and the orbiting electron
What is a molecule?
Atoms that combine together can form molecules
What is ionization?
When an atom gains or loses one or more electrons in order to have a full outer shell. An atom that gains or loses an electron and becomes electronically unbalanced is called an ion.
What charge is given to an ion when it loses an electron? When it gains one?
Positive when it loses one, negative when it gains
Where does the photon come from in dental x-rays?
From the tube head of the dental x-ray machine
What is radiation?
The emission and propagation of energy through space or a substance in the form of waves or particles
What is radioactivity?
The process by which certain unstable atoms or elements undergo spontaneous disintegration, or decay, in an effort to attain a more balanced nuclear state.
What is the definition of ionizing radiation?
Radiation that is capable of producing ions by removing or adding an electron to an atom
What is particulate radiation?
Tiny particles of matter that possess mass and travel in straight lines and at high speeds. There are four types.
