Atomic Structure

Atomic Structure

1. The Atom

   • Atoms can react together to form compounds
   • Elements: the simplest form of components of chemistry
     • There are approximately 92 different types of naturally occurring elements
     • atoms: the smallest unit of an element
   • Isotopes: Atoms of the same element with different numbers of neutrons
     • Radioisotopes
       • sterilize surgical instruments in hospitals
       • fight crime
       • detect cracks in structural materials
       • Cobalt-60 radio therapy
         • Treatment of cancer and other diseases with ionizing radiation
       • Carbon-14 dating
         • When organisms die, their age can be determined by measuring its rate of decay by determining its half life, the time it takes for half its atoms to decay.
       • preserve food
       • Iodine-131 medical tracer
         • Used to detect radiation levels in ones body. however, excessive use could also be harmful
       • Generate energy in nuclear power stations
   • John Dalton
     • Matter is composed of tiny indestructible particles called atoms
     • Atoms cannot be created nor destroyed
     • Atoms of different elements are different
     • Atoms can combine together in small numbers to form molecules
   • Enter text here
     • Mass number on top
     • Symbol of element in between
     • Atomic number at the bottom
   • Sub atomic particles
     • Nucleus
       • Neutron: no charge
       • Proton: positive charge
     • Electron: negative charge
       • Ions
         • Anions: gain an electron
         • Cations: lose an electron

2. The mass spectrometer

   • Vaporization: vaporization of injected sample
   • Detection: The beam of ions passing through the machine is detected electrically.
   • Deflection: The ions are then deflected by a magnetic field according to their masses. The lighter they are, the more they are deflected.
   • Acceleration: the positive ions are attracted to negatively charged plates and are accelerated by an electric field
   • Ionization: the atoms are made positive through bombardment of high energy electrons

3. Electron arrangement

   • Valence electrons: electrons found in the outer most energy level of an atom
   • Ionization energy: the minimum amount of energy required to remove an electron from the atom or molecule in the gaseous state.
   • Frequency
   • Wavelength
   • Continuous spectrum: made by white light when passed through a prism
   • Atoms
     • Excited state: high energy level Ground state: low energy level