Name one property which is shown by ammonium chloride but not by sodium chloride.

Name one common substance which can be easily changed from one state to another by heating or cooling.

What is the mane of the process in which:

(a) A solid turns directly into a gas?

(b) A gas turns directly into a solid?

What is the name of the process due to which dry ice changes into carbon dioxide gas?

What is the common name of solid carbon dioxide?