Chemistry

• Electrolysis is the breaking down of a substance using electricity
• In electrolysis, an electric current is passed through an electrolyte causing it to decompose
• In electrolysis, oxidation and reduction occur
• Cations move towards the cathode and are reduced
• Anions move towards the anode and are oxidised
• Reversible reaction: where the products can react with each other to produce the original reactants
• An example of a reversible reaction is: The Haber process
• Covalent bond: a strong bond that is formed when a pair of electrons is shared between two atoms
• Simple molecular substances are made up of molecules containing a few atoms joined by covalent bonds
• concentration = mass of solute/volume of solution
• moles = mass in g (element or compound)/Mr or Ar
• mass = number of moles x Mr or Ar
• Mr/Ar = mass/number of moles
• What is ionic bonding?

  The transfer of electrons
• In Ionic bonding, Metal and non metal react together
• In ionic bonding the metal atom loses electrons to form a positive ion
• In ionic bonding the non metal gains electrons to form a negative ion
• Ionic bond: the oppositely charged ions are strongly attached to one another by electrostatic forces