bonding, structure and properties of matter (2)

• compound


  substances in which 2 or more elements are chemically combined.
• ionic bonding

  Particles are oppositely charged ions, Occurs in compounds formed from metals combined with non-metals
• covalent bonding

  Particles are atoms which share pairs of electrons, Occurs in most non-metallic elements and in compounds of non-metals
• metallic bonding

  Particles are atoms which share delocalised electrons, Occurs in metallic elements and alloys
• ionic bonding

  metal + non metal: metal atoms lose electrons and become positively charged ions, non metal atoms gain electrons to become negatively charged ions. electron transfer can be represented by a dot and cross diagram
• ionic compounds

  giant structure of ions, held together by strong electrostatic forces between oppositely charged ions, the structure is 3D
• covalent bonding

  when atoms share one or more pairs of electrons, polymers are large covalently bonded molecules, giant covalent structures consist of atoms bonded in a lattice structure e.g. diamond.
• metallic bonding

  the bonding in a metal consists of positive ions and delocalised electrons arranged in a regular pattern, delocalised electrons are free to move through the structure, the delocalised electrons are shared through the structure so metallic bonds are strong.
• 3 states of matter

  solid, liquid, gas
• state symbol for solid

  s
• state symbol for liquid

  l
• state symbol for gas

  g
• state symbol for aqueous solutions

  aq
• properties for ionic compounds

  regular structures in which there are strong electrostatics forces of attraction in all directions between oppositely charged ions. high melting and boiling points because lots of energy is required to break many strong bonds. when melted or dissolved they conduct electricity because the ions are free to move around and carry current.
• properties of small molecules

  low boiling and melting points. weak intermolecular forces. don't conduct electricity
• properties of polymers

  large molecules. atoms are linked together by strong covalent bonds. strong intermolecular forces. solid at room temperature.
• giant covalent structures

  high melting points, due to strong covalent bonds, e.g. diamond and graphite
• properties of metals

  high melting points , high boiling points, layers of atoms slide over each other so metal can bend and be shaped
• properties of alloys

  made from 2 different types of metals, different size atoms distort the layers in the structure, making it harder to slide over each making they harder to bend and shape
• why are metals good conductors

  delocalised electrons can move through the metal carrying electricity.
• properties and structure of diamonds

  each carbon is joined to 4 other carbons covalently. it is very hard, has a high melting point and does not conduct electricity
• property and structure of graphite

  each carbon is covalently bonded to 3 other carbons, this forms layers of hexagonal rings. the layers can slide over each other but has weak intermolecular forces meaning graphite is soft and slippery. one electron from each atom is delocalised making it similar to metals and being able to conduct electricity.
• graphene


  single layer of graphite, strong because atoms within its layers are tightly bonded.
• fullerenes


  molecules of carbon atoms with hollow shapes
• what was the first fullerene discovered and what shape was it

  buckminster fullerene and a spherical shape
• carbon nanotube shape


  cylindrical
• uses of nanotubes 


  lubricants to deliver drugs around the body, reinforcing materials such as tennis rackets