chem

• ionic bonding properties?

  - elctrostatic force between opposite charged ions

  • high melting and boiling points
  • conduct electricity when molten or dissolved
  • brittle soluble in polar solution - because the opposite charged ions are attracted to water
• covalent bond?

  two non-metals share a pair of elctrons

  
  

  
  

  
  

  shorter the bond becomes the more energy it takes to break
• properties of covalent bonds?

  low melting and boiling points

  soft and brittle

  connot conduct electricity
• what are you breaking in covalent bonds?

  covalent you breaking the intermolecular forces between the molecule
• what is the meaning of dative covalent?

  Sharing of electron pairs in a covalent bond where both electrons come from one atom (when the actual atom has no electrons to share)
• single bond - 109.5 degree angle

  double bond - 120 degree angle
• metallic bond properties?

  meleable and ductile - because the presence of metal ions the layers can slide over each other and allows to shape it

  
  

  
  

  can conduct electricity in both solid and liquid - this is because due to the delocalised elctrons can carry charge

  
  

  
  

  high melting and boiling pointas - due to the strong elctrostatic force between metal ions and delocalised electrons - requiring large amount of energy to saparate
• the difference in the boiling points of the three copounds ?

  • hydrogen bonds are the strongest and have high boiling points
  • permenant dipole-dipole are the second strongest and have high boiling points therefore requires more energy to break the intermolecular forces
  • van der weels are the weakest therefore have low boiling points
• reactivity series?

  chloride ions form - white percepitate

  bromide ions form - cream percipitate

  iodide ions form _ yellow percipitate
• what is electronegativity?

  Electronegativity is the measure of an atom's ability to attract electrons in a chemical bond.
• explain the trend ionising energy across perid 2?

  1. as you move across period 2 the number of shells stays the same - this means electrons are added the same shells
  2. so nuclear attraction increase
  3. this means atomic radius across period 2 decreases
  4. the ionisation energy increases across the period
• what is the atomic radius?

  the distance between the nucleus and the last shell
• what is the ionisation energy mean?

  The energy required to remove an electron from an atom's outer shell