Question

Which of the following metals reacts with the moist carbon dioxide in the air and slowly loses its shiny brown surface and gains a green coat?
1. Silver
2. Zinc
3. Iron
4. Copper

Answer 1

Correct Answer - Option 4 : Copper

The correct answer is Copper.

•  Copper reacts with moist air and slowly loses its shiny brown surface and gains a green coat (or another colour depending on which component of air it reacts with).
• This process is called corrosion, which is a process that occurs when a metal is attacked by substances around it such as air, moisture, acids, etc.
• Copper
  • Copper is a chemical element with the symbol Cu 
  • Its atomic number is 29.
  • Copper is used as a conductor of heat and electricity.
  • It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity.
  • Copper is one of the few metals that can occur in nature in a directly usable metallic form.

•  Silver
  • Silver is a chemical element with the symbol Ag.
  • Its atomic number is 47.
  • It is a soft, white lustrous transition metal.
  • Most silver is produced as a byproduct of copper, gold, lead, and zinc refining.
• Zinc
  • Zinc is a chemical element with the symbol Zn.
  • Its atomic number is 30.
  • Zinc is a slightly brittle metal at room temperature and has silvery-greyish.
  • Zinc is refined by froth flotation of the ore, roasting, and final extraction using electricity.
• Iron
  • Iron is a chemical element with the symbol Fe.
  • Its atomic number is 26.
  • It is a metal that belongs to the first transition.
  • It is the fourth common element in the Earth's crust.