Question

Explain why ?

1. A gas fill a vessel completely? 

2. Camphor disappears without leaving any residue.

Answer 1

1. Because the molecules of the gas moves freely so it occupies the whole space the vessel. 

2. Camphor disappears after sometimes as its surface gains kinetic energy and gets directly converted into gas. The process of getting converted directly into gas without getting converted into liquid is called sublimation