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Sunday, July 6, 2025

Activity 3.2 Class 10 Science | Metals and Non-metals

We will observe and compare the hardness of various metals, including iron, copper, aluminium, magnesium, and sodium, in this activity.


Comparing the Hardness of Different Metals


Aim of the activity

 To compare the hardness of different metals.


Materials Required

   1. Samples of metals

   2. Knife

   3. Watch glass

   4. Tongs


Procedure

   1. Take samples of metals and try to cut each with a knife.

   2. Place a piece of sodium metal on a watch glass using tongs and cut with a knife


   Observation

   We observe that

     1.  Iron cannot be cut with a knife.

     2. Copper and aluminium can be cut with more effort.

  3. Magnesium is relatively soft and cut with some pressure.

    4. Sodium is very soft and it can be cut easily with a knife.


Explanation

Hardness is the physical property of metals.

Metals are quite hard, and their hardness varies from metal to metal. If we try to cut even a thin rod of iron into two pieces, it will be very difficult.  The same will be the case with metals like copper, silver, etc.

 But on the other hand, there are certain exceptions like sodium and potassium, which are soft and can be cut with a knife. The extent of hardness that a metal possesses depends upon the strength of the metallic bond.


Conclusion

This activity demonstrates the hardness of metals. We can conclude that –

    1. Iron and copper are very hard.

    2. Aluminium and magnesium are softer.

    3. Sodium is extremely soft.

This property of metals depends on their position in the periodic table.


Caution: Always handle sodium metal with care. Dry it by pressing between the folds of a filter paper.


 Frequently Asked Questions


   1. Why is sodium so easy to cut with a knife?

Answer – Sodium is an alkali metal and is very soft.


   2. Why is sodium kept in kerosene?

Answer – Sodium is highly reactive with water and moisture, so it is kept in kerosene.


 Related Topics - 

1.  Activity 3.3

2. Activity 3.1

3. Solution of Chapter 3 Metals and Non-metals

4. MCQ Questions of Chapter 3

5. Extra Questions of Chapter 3

6. Solutions of Class 10 Science all chapters

 

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