Question

What metal turns green when oxidized?

Answer 1

Corrosion:

• Corrosion is a natural process that causes the transformation of pure metals into undesirable substances when they react with substances like water or air.
• Corrosion makes the metal surface dull. Color change on the surface is also seen evidently due to corrosion.
• Copper ($\mathrm{Cu}$) is a metal that naturally turns green over time on oxidation.
• Therefore, the metal which turns green when oxidized is Copper.
• The reaction involved in this process is :

$\mathrm{Cu}\left(\mathrm{s}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)+{\mathrm{O}}_2\left(\mathrm{g}\right)+{\mathrm{CO}}_2\left(\mathrm{g}\right)\to \underset{(\mathrm{Green}\mathrm{in}\mathrm{colour})}{\underbrace{{\mathrm{CuCO}}_3\left(\mathrm{s}\right).\mathrm{Cu}{\left(\mathrm{OH}\right)}_2\left(\mathrm{s}\right)}}$