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Chemistry Form 4 • MODULE

(e) Apparatus: / Alat radas:
Retort stand and clamp, 1 kg weight, string, metre ruler.
Materials: / Bahan-bahan:
Steel ball, copper block, brass block

(f) Procedure: / Prosedur:
1. A steel ball bearing is tapped onto a copper block.
Satu bola keluli dilekatkan di atas sebuah bongkah kuprum. Set-up of the apparatus: / Susunan alat radas:
2. A 1 kg weight is hung at a height of 50 cm above the copper
block as shown in the diagram.
Sebiji pemberat 1 kg digantung setinggi 50 cm di atas bongkah kuprum
seperti yang ditunjukkan. Retort stand
3. Drop the 1 kg weight on the steel ball.
Pemberat 1 kg dijatuhkan ke atas bebola keluli.
4. Measure the diameter of the dent formed on the copper block String
with a ruler. 1 kg weight
Diameter lekuk yang terbentuk di atas bongkah kuprum diukur dengan
pembaris.
5. Repeat the experiment three times on the other part of the Steel ball
copper block.
Eksperimen diulang tiga kali, pada ruang berbeza pada bongkah kuprum Cellophane tape
yang sama.
6. Steps 1 to 5 are repeated using a brass block to replace the
copper block.
Langkah 1 hingga 5 diulang dengan menggunakan bongkah loyang, Copper block
menggantikan bongkah kuprum.

(g) Results: / Keputusan:
Experiment 1 2 3 Average diameter/cm
Eksperimen Diameter purata / cm

Diameter of dent on copper block/cm a b c a + b + c = x
3

Diameter of dent on brass block/cm d e f d + e + f = y
3

(h) Discussion: / Perbincangan:
The average diameter of dent on copper, x is larger than the average diameter of dent on brass, y.

(i) Conclusion: / Kesimpulan:
Brass is harder than copper// alloy is harder than pure metal.

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08-Chem F4 (3p).indd 173 12/9/2011 5:54:31 PM