Bonding

• Describe the structure of ionic compounds

  Giant lattice structure, every positive ion is surrounded by a negative ion bonded together by a strong electrostatic attraction (in a solid.)
• Conduction of electricity in ionic compounds

  ★ Ionic compounds can only conduct heat and electricity when molten or dissolved in water

  ★This is because only here the electrostatic force of attraction is broken

  𐬽The negatively charged ions can move freely

  𐬽The compound can conduct electricity
• Structure of small covalent molecules

  ★ Strong covalent bonds between the atoms

  ★ Weak intermolecular forces between the molecules
• Other properties of small covalent molecules (melts/boils,bigger,electricity)

  ★ Covalent bonds are not broken when the substance melts or boils

  ★ The larger the covalent molecules — the stronger the intermolecular forces

  𐬽 Higher m.p.s and b.p.s

  𐬽 More likely to be solid or liquid

  ★ They don't conduct electricity as there is not overall charge
• Explain metallic bonding


  ★ Metals consist of giant structures of atoms arranged in a regular pattern

  ★ Electrons are shared so there are free, delocalised electrons

  ➜ The electrons and the positive ions create a strong force of electrostatic attraction
• m.p/b.p of ionic compounds

  ★ High mp.p/b.p.

  ✔︎ This is because it takes a lot of energy to overcome the strong ionic bonds
• Do ionic compounds conduct electricity?

  ★ When molten or aqueous, ionic compounds can conduct electricity

  ✔︎ This is because:

  𐬽 The ions are free to move

  𐬽 Electricity can be conducted
• m.p/b.p of small molecules

  ★ Small molecules have a low m.p./b.p.

  ✔︎ This is because the intermolecular forces are very weak

  𐬽 It's very easy to overcome the forces and change state

  ⚠︎︎ The intermolecular forces become stronger with size

  𐬽 The higher the m.p./b.p.
• Can small molecules conduct electricity?

  ★ No as they have no charge