Question

napthalene balls disappear with the time without leaving any solid ? why .

Answer 1

napthalene ball show the property of sublimation and hence disappear without leaving any solid . They change directly to gaseous state from solid state...

Answer 2

Napthalene in a sublime substance and shows the property of sublimation,(Sublime substances change directly to gaseous state from solid state or vice versa and this is known as Sublimation) hence disappear without leaving any solid .