Dental - Radiation Physics

Front 1

Matter

Back 1

Anything that occupies space and has mass.

Front 2

Energy

Back 2

When matter is altered, energy results.

Front 3

Atom

Back 3

Fundamental unit of matter.

Front 4

T/F - All matter is composed of atoms, or tiny invisible particles.

Back 4

True

Front 5

Atom consist of 2 parts:

Back 5

1) a central nucleus
2) orbiting electrons

Front 6

Nucleus

Back 6

Dense core of the atom, is composed of particles known at protons and neutrons (also known as nucleons)

Front 7

Protons

Back 7

Carry positive electrical charges.

Front 8

Neutrons

Back 8

Carry no electrical charge.

Front 9

Mass number/Atomic weight

Back 9

Number of protons and neutrons in the nucleus of an atom.

Front 10

Atomic number

Back 10

The number of protons inside the nucleus equals the number of electrons outside the nucleus and determines the 'atomic number' of an atom.

Front 11

Elements

Back 11

Substances made up of only one type of atom.

Front 12

Electrons

Back 12

Tiny, negatively charged particles that have very little mass; an electron weighs approximately 1/1800 as much as a proton or neutron.

Front 13

Orbits/Shells

Back 13

Electrons travel around the nucleus in well-defined paths.

Front 14

Back 14

An atom contains maximum of 7 shells, each located at a specific distance from the nucleus and representing different energy levels. The shells are designed with the letters K, L, M, N, O, P, and Q; the K she'll is located closest to the nucleus and has the highest energy level.

Front 15

Binding energy, or binding force, of an electron.

Back 15

Electrons are maintained in their orbits by the 'electrostatic force', or attraction, between the positive nucleus and the negative electrons.

Front 16

K Shell

Back 16

Strongest binding energy is found closest the nucleus.
Electrons located in the outer shells have weak binding energy.

Front 17

Electron volts (eV)
Kilo electron volts (keV)

Back 17

Are what binding energies of orbital electrons are measured in.
(One kilo electron volt = 1000 electron volts)

Front 18

Maximum number of electrons each shell can hold:

Back 18

Front 19

Molecules

Back 19

Two or more atoms joined by a chemical bond, or smallest among of a substance that possesses it characteristics properties.

Formed in one of two ways:
1) by the transfer of electrons
2) by sharing of electrons between the outermost shells of atoms.
Example of simple molecule is water (H2O); the symbol H2 represents two atoms of hydrogen, and the symbol O represents one atom of oxygen.

Front 20

Neutral atom

Back 20

Contains an equal number of protons (+ charges) and electrons (- charges). Atoms can exist in a neutral state or in an electrically unbalanced state. Normally, most atoms are neutral.

Front 21

Ion

Back 21

An atom that gains or loses an electron and becomes electrically unbalanced.

Front 22

Ionization

Back 22

The production of ions, or process of converting an atom into ions. Deals only with electrons and requires sufficient energy to overcome the electrostatic force that binds the electrons to the nucleus.

Front 23

Ion pair

Back 23

When an electron is removed from an atom in the ionization process.

Front 24

Radiation

Back 24

The emission and propagation of energy through space or a substance in the form of waves or particles.

Front 25

Radioactivity

Back 25

The process by which certain unstable atoms or elements undergo spontaneous disintegration, or decay, in an effort to attain a more balanced nuclear state.

Front 26

Ionizing radiation

Back 26

Radiation that is capable of producing ions by removing or adding an electron to an atom.

Classified into 2 groups:
1) particulate radiation
2) electromagnetic radiation

Front 27

Particulate Radiation

Back 27

Tiny particles of matter that possess mass and travel in straight lines and high speeds. Transmit kinetic energy by means of their extremely fast-moving, small masses.

Front 28

4 Types of Particulate Radiation

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1 - Electron can be classified as beta particles or cathode rays.
2 - Alpha particles are emitted from the nuclei of heavy metals and exist as two protons and neutrons, without electrons.
3 - Protons are accelerated particles, specifically hydrogen nuclei, with a mass of 1 and a charge of +1.
4 - Neutrons are accelerated particles with a mass of 1 and no electrical charge.

Front 29

Beta Particles

Back 29

Fast-moving electrons emitted from the nucleus of radioactive atoms.

Front 30

Cathode Rays

Back 30

Stream of high-speed electrons that's originate in and x-Ray tube.

Front 31

Electromagnetic Radiation

Back 31

The propagation of wavelike energy (w/o mass) through space or matter.

Front 32

Electromagnetic Spectrum

Back 32

Electromagnetic radiation are arranged according to their energies.

Front 33

Photons/quanta

Back 33

Bundles of energy with no mass or weight that travel as waves at the speed of light and move through space in a straight line, 'carrying the energy' of electromagnetic radiation.

Front 34

Velocity

Back 34

Speed of the wave.
All electromagnetic radiations travel as waves or a continuous sequence of crest at the speed of light (3x108 meters per second [186,600 miles per second]) in a vacuum.

Front 35

Frequency

Back 35

Refers to the number of wavelengths that pass a given point in a certain amount of time.
High frequency = short wavelengths
Low frequency = long wavelengths