Radiation Concepts

basic building blocks of matter

atoms

how are elements arranged on the periodic table

by atomic number into families and groups

vertical groups

have same number of electrons in outer (valence) shell

horizontal periods

indicate elements have same number of electron shells

atomic nomenclature identifiers

atomic element symbol (chemical symbol), atomic mass (A#), atomic number (Z#)

nucleus

small dense center, contains nucleons (proton, neutron, others)

electrons

orbit nucleus in variety of planes, specific energy state

atomic number (Z#)

distinguish element by number of protons in nucleus

how does changing the number of neutrons or electrons affect an atom

changes the electrical stability

isotope

gain or lose neutron, different atomic mass

ions/ionization

gain or lose electron

when x-ray photons interact with an atom

an electron is ejected

ionization of atoms causes disruption to

the body’s metabolic relationship

isotope

elements can be found in different forms based on altered neutrons in a nucleus, indicate mass number as superscript

atomic mass (A#)

the number of protons and nuetrons

how to find number of neutrons in an atom

mass number (A/proton and neutron) - atomic number (Z/proton)

the distance from the nucleus determines the

shell the electron is in

order of shells

K, L, M, N, O, P, Q

electron capacity

2n² (where n indicated the orbital shell #)

The M shell can contain how many electrons

18 (2n²)

the further the electron is from the nucleus

the higher the energy level and less the binding energy

K shell orbital electrons

2, the strongest binding energy

L shell orbital electrons

8

M shell orbital electrons

18, more potential energy

electro binding energy increases as

Z# increases

electron binding energy is determined by

electron proximity to nucleus and % of protons in the nucleus

electron binding energy unit

electron volts (eV), energy of one electron when accelerated by one volt, same unit used to describe x-ray energy

chemical behavior determined by

valence band (outer shell)

chemical combining characteristic describes how

atom will bond to another (+1 gives up, -1 gains electron)

octet rule

atom never has more than eight electrons in outer shell

atom with eight electrons in outer shell is

chemically stable, inert, the noble gases

mass

quantity of matter, not influenced by gravity

weight

the force exerted due to gravity

matter can be a

substance (element/compound) or mixture

matter has

mass and takes up space

unit of mass

kg

unit of energy

joule (J)

energy is

force used to do work

radiation

emitted energy that is transmitted through matter

simple substance

element

smallest part of an element

atom

complex substance

compound

smallest part of a compound is

molecule

elements in human

oxygen, carbon, hydrogen, nitrogen, calcium, phosphorus, others

molecule

2 or more atoms chemically united, can be two of same element, held by chemical bonds

compound

type of molecule, different elements bound chemically, properties different than their elements

mixture

combination of two or more substances, not chemically bound, will separate

work

result of a force acting upon an object over a distance

physicist definition of work

work = force x distance

mechanical energy

result of action and physical movement, potential or kinetic

chemical energy

energy released by chemical reaction, usually converted to another energy (food/battery)

thermal energy

heat energy, result of movement of atoms and molecules, faster = more

electrical energy

study of resting or moving electrical charges, movement of electrons in conductor

nuclear energy

by breaking bonds between particles (nucleons) w/i nucleus

electromagnetic (EM) energy

combination of electric and magnetic fields traveling through space, wave like energy disturbance traveling through space, can travel through a vacuum

xrays are a form of

human made EM energy

EM energy is arranged according to

wavelength and frequency

EM energy is produced by

acceleration of a charge

electromagnetic spectrum

waves change gradually from lowest (radio/micro) to highest (xray/gamma)

one of the common properties of all forms of EM radiation is

velocity

EM radiation velocity

speed of light (3×10^8 meter per second) in a vacuum

speed of light is a

constant (denoted by c)

discovery of xrays

Wilhelm Rontgen, Nov. 8, 1895

first nobel prize winner for physics (1901)

behavior of electrons traveling through glass tube, use of barium platinocyanide as fluorescent

first recognized xray image

wife left hand with ring on finger

fundamental properties of xrays

• travel in straight line

• highly penetrating, invisible

• electronically neutral

• polyenergetic and heterogenous

• travel at speed of light

• release heat passing matter

• can ionize matter

• cause fluorescence of crystals

• cant be focused by lens

• affect photo film

• chemical/biological change in matter through ionization/excitation

• produce secondary/scatter radiation

K shell electron binding energy for tungsten

69.5 keV