Page 11 - Nilam_Publication_module_Chemistry_Form.pdf

Chemistry Form 4 • MODULE

3 The constant temperature at which a liquid changes to a solid is called freezing point . During the freezing
process, the temperature remains unchanged because the heat released to the surrounding is balanced by the
heat released when the liquid particles rearrange themselves to become a solid .
Suhu tetap di mana suatu cecair berubah kepada keadaan pepejal dipanggil takat beku . Semasa proses
pembekuan, suhu tidak berubah kerana haba yang dibebaskan ke persekitaran diimbangi oleh haba yang terbebas
apabila zarah-zarah cecair menyusun semula untuk membentuk pepejal .

Keadaan Fizik Bahan pada Sebarang Suhu: / Physical State Of A Substance At Any Given Temperature:
1 A substance is in solid state if the temperature of the substance is below melting point
Suatu bahan berada dalam keadaan pepejal jika suhu bahan tersebut lebih rendah daripada takat leburnya.

2 A substance is in liquid state if the temperature of the substance is between melting and boiling points.
Suatu bahan berada dalam keadaan cecair jika suhu bahan tersebut berada antara takat lebur dan takat didihnya.

3 A substance is in gas state if the temperature of the substance is above boiling point.
Suatu bahan berada dalam keadaan gas jika suhu bahan tersebut lebih tinggi daripada takat didihnya.

EXERCISE / LATIHAN

1 The table below shows substances and their chemical formula.
Jadual di bawah menunjukkan bahan dan formula kimia masing-masing.

Substance / Bahan Chemical formula / Formula kimia Type of particle / Jenis zarah
Silver / Argentum Ag Atom

Potassium oxide / Kalium oksida K O Ion
2
Ammonia / Ammonia NH Molecule
3
Chlorine / Klorin Cl Molecule
2
(a) State the type of particles that made up each substance in the table.
Nyatakan jenis zarah yang membentuk bahan dalam jadual di atas.
(b) Which of the substances are element? Explain your answer.
Yang manakah antara bahan tersebut merupakan suatu unsur? Jelaskan jawapan anda.
Silver and chlorine. Silver and chlorine are made up of one type of atom
(c) Which of the substance are compound? Explain your answer.
Yang manakah antara bahan tersebut merupakan suatu sebatian? Jelaskan jawapan anda.
Potassium oxide and ammonia. Potassium oxide and ammonia are made up of two different elements

2 The table below shows the melting and boiling points of substance P, Q and R.
Jadual di bawah menunjukkan takat lebur dan takat didih bagi bahan P, Q dan R.

Substance / Bahan Melting point / Takat lebur / °C Boiling point / Takat didih / °C
P –36 6
Q –18 70

R 98 230

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