cells and batteries (triple)

• Cell


  Two different metals placed in an electrolyte to produce electricity
• Producing electricity in a cell

  1. Chemical reaction on the surface of the two metals

  2. Potential difference and electric current generated
• A simple cell does not generate electrical current for long
• Cells only produce electricity if metals with different reactivity are used
• Reactivity series of metals

  • Reactive metals at the top (e.g. magnesium, aluminium)
  • Less reactive metals at the bottom (e.g. lead, copper)
• Difference in reactivity between metals

  Determines size of potential difference produced by the cell
• Battery


  Two or more cells connected in series to produce a greater voltage
• Alkaline batteries are non-rechargeable as the reactions cannot be reversed
• Rechargeable batteries can have their chemical reactions reversed by applying an electrical current