C2 B,S,P

• why do group 1 and 2 elements often form ions?


  only need to lose 1 or 2 electrons to be stable which doesn't require much energy
• why do group 6 and 7 elements often form ions?

  only need to gain 1 or 2 electrons to be stable which doesn't require much energy
• why are group 3 ,4 and 5 elements not often found as ions?

  need to gain or lose 3-4 electrons which requires too much energy
• describe the structure of ionic compounds

  regular giant lattice structure
• why do ionic compounds have a high melting point?

  loads of ionic bonds which are really strong require a lot of energy to break
• can ionic compounds conduct electricity?

  yes but only when melted or dissolved in water so ions are free to move
• what is a simple molecule?

  strong covalent bonds with weak intermolecular forces
• why do simple molecules have a low melting point?

  weak intermolecular forces do not require much energy to break
• define giant covalent structure

  large number of non-metal atoms bonded by covalent bonds
• describe bonding of graphite

  each carbon atom bonded to 3 others
• describe structure of graphite

  hexagonal rings in layers
• why is graphite a conductor?

  each carbon atom has 1 delocalised electron that is free to move around the structure
• describe bonding of diamond

  carbon forms 4 covalent bonds
• describe structure of diamond

  regular tetrahedral structure
• is diamond a conductor and why?

  no because diamond does not have delocalised electrons
• what is graphene?

  single layer of graphite
• what is graphene used in?

  electronics and composits
• describe fullerene

  molecules of carbon atoms with hollow shapes
• what are fullerene molecules held together by and what does this mean?

  weak intermolecular forces which mean molecules can slide over each other
• what is buckminsterfullerene ?

  first fullerene discovered
• what is buckminsterfullerene made of?

  60 carbon atoms
• why does buckminsterfullerene have a low melting point?

  weak intermolecular forces do not require much energy to overcome
• what is a nanotube?

  layer of graphene rolled into a cylinder
• list to features of nanotubes

  high length to diameter ratio

  high tensile strength
• what do nanotubes' high tensile strength mean and why is this useful?

  difficult to break when pulled mean its useful in electronics
• describe the structure of metals

  giant structure of atoms arranged in a regular pattern
• what happens with electrons during metallic bonding?

  atoms give up their outer shell electrons and share them with all other atoms
• what do atoms in metallic bonding become?

  positive ions
• what creates the metallic bond?

  the electrostatic force between the electrons and positive ions
• what are properties of metals?

  Malleability, ductility, conductivity, luster, and high melting and boiling points.
• what is an alloy?

  a mix of 2 or more different elements
• why are alloys harder than pure metals?

  the different sized atoms disrupt the regular structure so layers can no longer slide over each other