Rusted metal. Image credit

Rusted metal. Image credit

ZIMSEC O Level Combined Science Notes: Experiment:To compare the effects of atmospheric corrosion on metals

Aim: To compare the effects of atmospheric corrosion on various metals

Materials:  samples of mild steel/cast iron, stainless steel, cutting steel (razor blade/old hacksaw blade), brass, aluminium, copper, plastic lids or glass beakers


  1. Place each sample metal in a beaker or on a lid
  2. Add water to each one making sure not to cover each one, only add enough water to create a moist environment
  3.  Observe each metal once a week for several week adding water if the beakers dry out

Observation and Results

  • Copper and Aluminum resist corrosion best
  • Cast iron rusts easily
  • Stainless steel and cutting steel also resist rust


  • Less reactive metals like copper resist corrosion
  • Stainless steel is resistant to corrosion
  • Aluminum forms an oxide layer that protects it from rusting/corrosion
  • Cast iron/mild steel rusts easily

To access more topics go to the Combined Science Notes page