Question

naphthalene balls disappear with time without leaving any solid​

Answer 1

naphthalene balls disappear with time without leaving any solid​ because they are subliments. They transform from solid to gas without going through liquid and vice versa

Answer 2

Napthalene balls dissappear with time without leaving any solid due to a process called sublimation.

Sublimation is a process of converting solid into vapour or vice versa