bonding/structure/properties of matter

• ions are made when electrons are transferred
• ions are charged particles
• when metals form ions, they lose electrons from their outer shell to form positive ions
• when non metals form ions, they gain electrons into their outer shell to form negative ions
• ionic bonding is between a metal and non metal
• ionic bonding 


  the metal loses electrons to form a positively charged ion and the non metal gains these electrons to form a negatively charged ion. this creates an electrostatic forces
• dot and cross diagrams represent ionic bonding
• ionic compounds have a structure called a giant ionic lattice
• ionic lattice


  ions form a closely packed regular lattice arrangement, very strong electrostatic forces of attraction between oppositely charged ions in all directions in the lattice
• ionic compounds

  • high melting points
  • high boiling points
  • cannot conduct electricity
  • dissolve in water
• group 1 elements form 1+ ions
• group 2 elements form 2+ ions
• group 6 elements form 2- ions
• group 0 elements form 1- ions
• covalent bonding is non metals
• you can represent covalent bonds by a dot and cross diagram
• substances containing covalent bonds usually have simple molecular structures
• atoms within simple molecular structures are held by very strong covalent bonds but the attraction between the molecules are weak
• boiling and melting point of simple molecular structures are very low
• to melt or boil a simple molecular structure you must break the intermolecular forces NOT the covalent bonds
• most molecular substances are gases or liquids at room temperature
• the bigger the molecule, the stronger the intermolecular forces therefore more energy is needed to break them
• molecular compounds do not conduct electricity
• molecular compounds do not have any free electrons and are not charged
• polymers are long chains of repeating units to form a long molecule
• polymers are joined by strong covalent bonds
• most polymers are solid at room temperature
• the intermolecular forces in polymers are stronger therefore need more energy to break them
• polymers have lower boiling points than ionic or giant molecular compounds
• giant covalent structures are made up of strong bonded covalent bonds
• giant covalent structures have very high melting and boiling points
• a lot of energy is needed to break giant covalent structures
• giant covalent structures do not conduct electricity and do not contain charged particles
• giant covalent structures: diamond , graphite , silicon dioxide
• polymers are represented with an: n
• diamond is a covalent structure which has a very high melting point and does not conduct electricity
• diamond is made up of four covalent bonds
• graphite contains sheets of hexagons
• graphite has a high melting point, the covalent bonds in the layers need a lot of energy to break
• in graphite, each carbon atom only forms three covalent bonds creating sheets of carbon atoms arranged in hexagons