Question

Which process do napthalene balls undergo when left open?

Answer 1

Naphthalene balls undergo sublimation when kept open.
In the process of sublimation, a solid substance directly gets converted into gaseous state without a liquid interstate.
So, when napthalene is kept open, it directly gets converted into naphthalene vapours(gaseous). This property of naphthalene balls is used as a pest remover for killing cockroaches and other pests that may damage dresses kept in wardrobe.