Activity 3.1 Class 10 Science

In this activity, we will examine and compare the physical appearance of different metals.

Comparing the Appearance of Metals

Aim of the activity

To observe and compare the appearance of iron, copper, aluminium, and magnesium

Materials Required

    1.  Iron

    2. Copper

    3. Aluminum

    4. Magnesium

    5. Sandpaper

Procedure

We take a small sample of four metals -iron, copper, aluminium, and magnesium and place them on a table. Now we observe their colour and surface appearance.

Next, we take a piece of sandpaper and rub the surface of each metal sample to remove dirt and the oxide layer.

After rubbing, we observe each metal and note the changes in its appearance.

Observation

Metal	Before cleaning	After cleaning
Iron	Dull grey, rust patches	Shiny grey surface
Copper	Brownish or greenish layer	Reddish brown shiny surface
Aluminium	Dull grey or white oxide layer	Silvery white
Magnesium	Oxide layer	Shiny silver surface

 

Explanation

Metals react with oxygen in the air, forming a thin layer of oxide on their surface. When we rub the metal with sandpaper, the oxide layer is removed, and a shiny, lustrous surface appears.

Conclusion

This activity demonstrates that luster is a characteristic property of metals, but this becomes dull due to the formation of an oxide layer on its surface.

Frequently Asked Questions

    1. Why does the metal appear dull before cleaning?

Answer – Due to the formation of oxide layers on their surface.

    2. Can oxide layers protect metals?

Answer – In most cases, the oxide layer on aluminium protects against further corrosion.

    3. What does this activity show about metals?

Answer – Metals are lustrous.

4.