This happens because of corrosion of copper , as the copper is exposed to air it reacts slowly with water from the moisture present in air, carbondioxide and oxygen. And the product formed is a mixture of copper hydroxide and copper carbonate as shown below.
Why does copper turns green on exposure to air ?
Published by Ankush Sharma
I am M.Sc (chemistry ) from Punjabi University Patiala. I am a science teacher with expertise in chemistry, with 8 years of experience in teaching. Writing and blogging is my hobby, I write whenever I am free. I am constantly working on creating a new and easy way of learning the tough things in an effective way. I am constantly working to make authentic and reliable information to be shared with my students and widen the horizons of knowledge. View more posts