Sublimation is the process by which a substance transitions directly from a solid to a gas without passing through the liquid phase. It occurs when the substance's vapor pressure exceeds its melting point at the given temperature and pressure. To demonstrate sublimation, we can perform an activity involving the sublimation of a common substance like camphor.

Materials needed:
1. Camphor tablets
2. Heat source (a candle or a Bunsen burner)
3. Metal spoon or tongs
4. Heat-resistant surface or plate

Procedure:

1. Safety precautions:
- Ensure you are working in a well-ventilated area to avoid inhaling the camphor vapor.
- Use caution when handling the heat source to prevent burns or accidents.
- Keep flammable materials away from the heat source.

2. Set up:
- Place the heat-resistant surface or plate on a stable and heat-resistant surface.
- Place the heat source (candle or Bunsen burner) on the surface, making sure it is secure and stable.

3. Lighting the heat source:
- Safely light the candle or Bunsen burner using a match or a lighter.
- Adjust the flame to a moderate size, ensuring it is not too large or too small.

4. Placing the camphor:
- Using a metal spoon or tongs, pick up a small camphor tablet.
- Hold the camphor tablet over the flame, ensuring it does not touch the flame directly.
- Keep the tablet in the flame for a few seconds, allowing it to heat up.

5. Sublimation process:
- Observe the camphor tablet as it starts to vaporize without melting into a liquid.
- Notice the white smoke-like substance rising from the tablet.
- The camphor tablet undergoes sublimation, transitioning directly from a solid to a gas.

6. Safety precautions and clean-up:
- Once the demonstration is complete, carefully extinguish the flame.
- Allow the camphor tablet residue to cool down completely before disposing of it.
- Clean the heat-resistant surface or plate, ensuring it is free from any residue or debris.

This activity visually demonstrates the sublimation process by observing the camphor tablet directly transforming from a solid to a gas without an intermediate liquid phase. It highlights the concept of sublimation, where certain substances can undergo this unique phase change under specific conditions.