atomic structure

• Mixture


  A mixture is composed of two or more substances mingled together but not chemically combined.
• Evaporation


  can be used to separate a soluble solid from a liquid e.g salt and water
• chromatography


  is a technique used to separate substances carrying them different distances in a solvent along chromatography paper.
• Distillation


  This method can be used to separate a soluble solid from a liquid just like evaporation
• filtration


  This is a method used to separate an insoluble solid from a liquid.
• soluble


  this is when something dissolves in a solvent
• insolube


  this is when it doesn't dissolve in a solvent
• Periodic Table


  A chart of the elements showing the repeating pattern of their properties

  
• How is the Periodic Table arranged?

  By atomic number
• Mendeleev


  A Russian chemist. He is credited as being the primary creator of the first version of the periodic table of elements. Though there were other contributors to the table, Mendeleev predicted the properties of elements yet to be discovered.
• Groups or Families


  The vertical columns on periodic table. These elements have similar chemical and physical properties.

  
  

  The elements in each group have the same number of electrons in the outer orbital (*see valence electrons)
• Periods


  Each horizontal row on the periodic table is called a period. Elements in periods are not alike in properties. First element in a period is always extremely active and the last is always an inactive gas

  
  

  All of the elements in a period have the same number of energy levels/orbitals.
• Alkali Metals


  Group 1

  1 valence electron

  +1 charge

  Very reactive

  Form (+) ions

  Metals (shiny, conduct electricity, ductile)

  
• Alkali Earth Metals


  Group 2

  2 valence electrons

  +2 charge

  Form (+) ions

  Metals (shiny, conduct electricity, ductile)

  
• Halogens


  Group 17

  7 valence electrons

  -1 Charge

  Form (-) ions

  Nonmetals

  
• Noble Gases


  Group 18

  8 valence electrons

  0 charge (no charge)

  Do not react with other

  
• valence electrons


  Electrons on the outermost energy level of an atom.

  These are the electrons that are gained or lost when bonds are formed.
• Metals


  Characteristics such as malleable, ductile, shine and conductivity
• Nonmetals


  Elements that are usually dull in appearance, poor conductors of heat and electricity, gases at room temperature
• Metalloids


  Elements that have properties of both metals and nonmetals.

  
  

  Elements along the stair-step line:

  B, boron; Si, Silicon; Ge, germanium;

  As, arsenic; Sb, antimony;

  Te, tellurium; Po, polonium; At, astatine
• group 1

  
• group 2

  
• group 3

  
• group 4

  
• group 5

  
• group 6

  
• group 7

  
• group 8

  
• noble gases

  
• Atomic Number


  Number of protons in an atom

  
• Atomic Mass


  total weight of protons and neutrons

  
• atom


  smallest unit of matter

  
• nucleus of atom


  the positively charged dense center of an atom

  
• neutron


  A subatomic particle that has no charge and that is found in the nucleus of an atom

  
• proton


  A subatomic particle that has a positive charge and that is found in the nucleus of an atom

  
• electron


  A subatomic particle that has a negative charge

  
• Atoms are neutral because they have an equal number of positive charges (protons) and negative charges (electrons).
• The number of protons is equal to the number of electrons.
• Ions are atoms that have gained or lost one or more electrons, resulting in a net charge.