•Take some camphor or ammonium chloride.crush it and put in in a China dish.

Activity to show sublimation of Ammonium Chloride:

To demonstrate the sublimation of Ammonium Chloride, we can perform the following activity:

Materials needed:
1. Ammonium Chloride (NH4Cl)
2. Test tube
3. Bunsen burner
4. Cork stopper
5. Glass tube
6. Ice

Procedure:
1. Take a small amount of Ammonium Chloride (NH4Cl) in a test tube.
2. Attach a cork stopper to the test tube, ensuring that a glass tube is inserted into the cork. This glass tube will act as a condenser.
3. Place the test tube in a beaker containing ice to keep it cool.
4. Heat the test tube gently using a Bunsen burner flame.
5. Observe the phenomenon occurring inside the test tube.

Observations:
1. Initially, Ammonium Chloride is in solid form.
2. As the test tube is heated, the Ammonium Chloride starts to sublime.
3. White fumes are observed coming out from the test tube.
4. These fumes condense in the cooler part of the glass tube, forming a white solid.

Explanation:
The process observed in this activity is known as sublimation. Sublimation is the phase transition where a substance changes directly from a solid state to a gaseous state without passing through the liquid state.

In this case, as Ammonium Chloride is heated, it undergoes sublimation, and white fumes are produced. These fumes consist of gaseous Ammonium Chloride molecules. When these molecules come in contact with the cooler part of the glass tube, they condense and form solid Ammonium Chloride again.

This phenomenon occurs due to the unique properties of Ammonium Chloride. It has a relatively low melting point and a high vapor pressure at room temperature. When heated, the solid Ammonium Chloride molecules gain enough energy to overcome the intermolecular forces holding them together, and they escape into the gas phase. Upon cooling, these gas molecules lose energy and condense back into solid form.

The sublimation of Ammonium Chloride can be useful in various applications, such as in the production of smoke screens, in fire extinguishers, and in certain chemical processes.

Overall, this activity visually demonstrates the sublimation process, which is the direct conversion of a solid into a gas without an intermediate liquid phase.