The Structure Of Matter Flashcards
Greek Atom
Atomos means indivisible
How many elements are there
112
How many elements are naturally occurring and artificial
92 naturally occurring, 20 artificially produced
Smallest particle that has all the properties of an element
Atom
Particle smaller than atom
Subatomic Particles
Hook-and-eye affair
Dalton Atom
Showe that elements can be classified acc to integral values if atomic mass
John Dalton 1808
First periodic table of elements
Dmitri Mendeleev
Group 1 elements, all soft metals combine readily w/ oxygen and violent w/ water
Alkali Metals
Group VII elements
, Easily vaporized & combine with metals to
form water-soluble salts
Halogens
Group VIII elements
Highly resistant to reaction with other
elements
Noble Gas
Plum pudding
Thomson Atom
He investigated the physical properties of cathode rays (electrons)
J.J. Thomson (1890)
He described the atom as containing a small,
dense, positively charged center surrounded
by a negative cloud of electrons
Ernest Rutherford (1911)
He described the atom as containing a small,
dense, positively charged center surrounded
by a negative cloud of electrons
Ernest Rutherford (1911)
Miniature solar system
Bohr Atom (1913)
More accurately described the details of
atomic structure
Quantum-chromodynamics (QCD)
Atom smasher, used in mapping the structure of atomic
nucleus
Particle Accelerator
It is composed of quarks & gluons
(subatomic particles
Nucleons
fundamental particles of an atom
electron, proton & the neutron
The mass of a neutral atom of an element
Atomic Mass Unit
Number of protons plus number of neutrons
in the nucleus
Atomic Mass Number
Same number of electrons & protons
Neutral Atom
Determine the chemical behavior of an atom
Number of Protons
Same number of protons, but different
number of neutrons
Isotopes
Max No. Of outer shell
Eight
Maximum Electrons Per Shell
2n2
The shell number
Principal Quantum Number
Orderly Scheme of Atomic Progression
Interrupted in fourth period
Atoms associated with the phenomenon
orderly scheme of atomic progression
Transitional elements
The force that keeps an electron in orbit
Centripetal Force
The force that causes an electron to travel
straight and leave the atom
Centrifugal Force
The strength of attachment of an electron to
the nucleus
Electron Binding Energy
The primary constituents of x-ray tube target
Tungsten (W-74) & Molybdenum (Mo-42)
Radiographic & fluoroscopic contrast agents
Barium (Ba-56) & Iodine (I-53)
The important component of human tissue
Carbon (C-6)
The amount of energy (34 keV) necessary to
ionize tissue atoms
Ionization Potential
The alphabetic abbreviations of an element
Chemical Symbols
It determines the chemical properties of an
element
Number & Arrangement of Electrons
Atomic number
Number of Protons
Number protons plus number of neutrons
Atomic Mass Number
it is the arbitrary standard for
atomic measure
Carbon-12 Atom
It is determined by the relative abundance of
isotopes & their respective atomic masses
Elemental Mass
It occurs when the nucleus contains too few
or too many neutrons
Technetium-99m (Tc-43)
Radioactive atoms that have the same
number of protons
Radioisotopes
Two primary source of naturally occurring
radioisotopes
Uranium (U-92) & Carbon-14
It occurs in all radioisotopes
Beta Emission
It occurs only in heavy radioisotopes
Alpha Emission
The time required for a quantity of
radioactivity to be reduced to one-half its
original value
Radioactive Half-life
It described the rate of radioactive decay &
the quantity of material present at any given
time
Radioactive Decay Law
Five Physical Characteristics of Ionizing Radiation
Mass, Energy, Velocity, Charge & Origin
It has finite range in matter
Particulate Radiation
The same with mass electrons
Positive beta particles
The same with electrons, only differ in origin
Negative Beta Particles
No mass and no charge, travels in the soeed of light
Photons
Type of radiation used in MRI and UTZ
Non-ionizing radiation
