Periodicity

• Factors affecting ionisation energy

  • Nuclear charge/attraction
  • atomic radius
  • electron shielding
• trends in 1st ionisation energies down a group

  as you go down a group, nuclear attraction decreases as the atomic radius between the electron and the nuclear increase and also the electron shielding increases, therefore ionisation energy decreases as you move down the group as it easier to lose an electron.
• trends in 1st ionisation energies across a period

  as you move across a period the nuclear charge increases and the electron shielding remains similar as they’re in the same shell but atomic radius decreases so therefore the ionisation energy increases
• arrangement of elements in the periodic table 


  elements are arranged in order of increasing atomic number
• ionisation energy definition 


  the energy required to remove 1 mole of electrons from each atom in a mole of atoms in the gaseous state
• Metallic bonding and structure

  • Consists of giant metallic lattice
  • conducts electricity in solid and liquid due to delocalised electrons in the structure being able to carry charge around the whole structure
  • force - electrostatic attraction between cations and delocalised electrons
  • has a high melting and boiling point as it requires lots of energy to overcome the strong forces
• giant covalent lattices

  • consists of covalent bonding
  • has a high melting and boling point as it requires lots of energy to overcome the forces
  • is insoluble
  • doesn’t conduct electricity except for graphene and graphite due to a free electron not involved in covalent bonding which can carry charge around the structure
• trends in melting point across a period

  • high melting point between groups 1 to 4 (metals)
  • sharp decrease between groups 4 to 5 ( giant covalent)
  • relatively low between groups 5 to 8 ( simple molecular structures)