Page 2 - 3. Lesson Notes - Ch-3 Uses of Metals & Nonmetals (Alloys)

• Chlorine is a powerful disinfectant. It is used to purify water for drinking
and fill swimming pools
➢ 10 common uses of metals in our daily life☆☆☆

1) Gold, Platinum and silver are used as jewelleries and ornaments.

2) Iron and steel are used for construction purpose.

3) Aluminium and stainless steel are used for making utensils.

4) Mercury is used in thermometer and helps to check the temperature.

5) Aluminium is used for making frames of doors & windows..

6) Aluminium foils are used as food wrappers.

7) Silver foil is used in sweets.

8) Zinc is used for galvanising to prevent rusting.

9) Iron is used in automobiles.

10) Copper is used for making cable wires.

➢ Alloys-
❖ Many metals are used in the form of their Alloys-
• Alloying is a very good method of improving the properties of a
metal and reducing the rate of corrosion in some cases

• We can get the desired properties by alloying metals with other
metals or non-metals (non-metals used may be carbon/silicon).

❖ An alloy is a homogeneous mixture of two or more metals, or a
metal and a nonmetal.

❖ Preparation of an Alloy-
Step 1- It is prepared by first melting the primary metal, and then,
dissolving the other elements in it in definite proportions.

Step 2- It is then cooled to room temperature to get the desired alloy.

Example-
1. Iron is the most widely used metal…
But it is never used in its pure state but usually alloyed with other metals/ non-
metals.
Reason- This is because pure iron is very soft and stretches easily when hot.

i. Steel- When it is mixed with a small amount of carbon (about 0.05 %),
it becomes hard and strong. This is known as Steel.

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