periodi table

• Organic chemistry


  The study of carbon-based compounds
• Inorganic chemistry


  The study of all other compounds that are not organic
• Saturated hydrocarbon


  A hydrocarbon with only single bonds between carbon atoms
• Unsaturated hydrocarbon


  A hydrocarbon with at least one double or triple bond between carbon atoms

  
• Dimitry Ivanovich Mendeleev


  • Discovered the modern periodic table by grouping elements according to their physical and chemical properties

  
• Julius Lothar


  • Discovered the modern periodic table by grouping elements according to their physical and chemical properties

  
• Antoine-Laurent de Lavoiser


  • Arranged the first true periodic table
• Johann Dobereiner


  • Arranged elements by their similarity into groups of three, called the Triad
• John Newland


  • Established the Law of Octaves and grouped elements known in his time in order of relative atomic mass
• Henry Mosley


  • Devised the presently used Periodic Table which he arranged by atomic number
• Bonding


  The joining of two atoms in a stable arrangement

  
• Ionic bond


  Results from the transfer of electrons from one element to another

  
• Covalent bond


  Results from the sharing of electrons between two atoms

  
• Ionic bond


  • Occurs between atoms of metals and nonmetals with very different electronegativity
  • The more electronegative atom gains one or more valence electrons and becomes an anion; the less electronegative atoms loses one or more valence electrons and becomes a cation
  • Bond formed by transfer of electrons
  • Produce ionized particles that are conductors and have high melting point

  
• Covalent bond


  • Occurs between two or more nonmetallic elements of similar electronegativity
  • Formed by sharing electron pairs
  • Stable non-ionizing particles, they are not conductors at any state
  • Bonds in all the polyatomic ions and diatomic molecules are all covalent bonds
  • Can be polar and nonpolar

  
• Nonpolar covalent bond


  Occurs between atoms with small electronegativity difference (<0.5 Pauling units), where electrons are shared equally

  
• Polar covalent bond


  Occurs between atoms with moderate electronegativity difference (0.5 and 1.9 Pauling units), where electrons are not shared equally

  
• Electronegativity


  A measure of an atom's attraction for the electrons it shares in a chemical bond with another atom