Write true or false for the following statement:
Due to corrosion, iron gets a brown coating, copper gets a green coating, and silver gets a black coating.

What is the chemical formula of rust?

If copper is kept open in air,it slowly loses its shining brown surface and gains a green coating. It is due to the formation of

$A$ student has been collecting silver coins and copper coins. One day she observed a black coating on silver coins and a green coating on copper coins. Which chemical phenomenon is responsible for these coatings? Write the chemical name of black and green coatings.

Which of the following gases can be used for the storage of a fresh sample of an oil for a long time?

$A$ silver article generally turns black when kept in the open for a few days. The article when rubbed with toothpaste again starts shining.
$(a)$ Why do silver articles turn black when kept in the open for a few days? Name the phenomenon involved.
$(b)$ Name the black substance formed and give its chemical formula.