Topic 10-making electricity

A cell, often reffered to as a battery, contains chemicals which react to produce electricity. In dry cells the chemicals are used up and then have to be replaced.

• When metals form ions, they give away one or more elecctrons 
• some reactive metals (eg lithium, sodium) lose electrons very easily
• other metals (eg gold, silver) do not give electrons away very easily
• The electrochemical series ranks the metals in order of reactivity

Electricity from pairs of metals

• Electricity is produced when two differant metals are dipped in an electrolyte and connected with a wire
• We measure metals giving away their electrons in volts
• In a cell the more reactive metal gives its electrons to the less reactive metal
• Electrons flow through the wire and ions move throough the electrolyte
• Electrons cannot move through a solution

Cells made from two half-cells

• You can produce electricity from a cell which is made of two different metals where the metals are dipping in a solution of their own ions
• the essential features of a simple cell
  • there are two different metals 
  • the metals are separated from each other by an electrolyte
  • the metals are connected by wires through which electrons can…