Page 43 - NCERT Science Class 10 English Medium

You will find that metals are generally hard. The hardness varies
from metal to metal.

Activity 3.3
Activity 3.33.3
Activity
Activity 3.3
Activity 3.3
n Take pieces of iron, zinc, lead and copper.
n Place any one metal on a block of iron and strike it four or five
times with a hammer. What do you observe?
n Repeat with other metals.
n Record the change in the shape of these metals.

You will find that some metals can be beaten into thin sheets. This
property is called malleability. Did you know that gold and silver are the
most malleable metals?

Activity 3.43.4
Activity 3.4
Activity 3.4
Activity 3.4
Activity
n List the metals whose wires you have seen in daily life.
The ability of metals to be drawn into thin wires is called ductility.
Gold is the most ductile metal. You will be surprised to know that a wire
of about 2 km length can be drawn from one gram of gold.
It is because of their malleability and ductility that metals can be
given different shapes according to our needs.
Can you name some metals that are used for making cooking vessels?
Do you know why these metals are used for making vessels? Let us do
the following Activity to find out the answer.

Activity 3.5
Activity 3.5
Activity
Activity 3.5
Activity 3.53.5
n Take an aluminium or copper
wire. Clamp this wire on a
stand, as shown in Fig. 3.1.
n Fix a pin to the free end of the
wire using wax.
n Heat the wire with a spirit lamp,
candle or a burner near the
place where it is clamped.
n What do you observe after some
time?
n Note your observations. Does
the metal wire melt?

Figure 3.1
Figure 3.1
Figure 3.1
Figure 3.1
Figure 3.1
Metals are good
conductors of heat. The above activity shows that metals are good conductors of heat
and have high melting points. The best conductors of heat are silver and
copper. Lead and mercury are comparatively poor conductors of heat.
Do metals also conduct electricity? Let us find out.

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