EXERCISES OF CHAPTER 4
Date of submission: Before the upcoming class
1. The table shows the electron arrangement of atoms of elements T, Q and R. The letters are not
the actual symbols of the elements.
Jadual di bawah menunjukkan susunan elektron bagi atom unsur T, Q dan R. Huruf yang
digunakan adalah bukan simbol sebenar bagi unsur itu.
Atom
Atom
Electron arrangement
Susunan elektron
T
2.1
Q
R
2.8.8.1
a) T, Q and R are located in the same group in the Periodic Table of Elements.
T, Q dan R berada pada kumpulan yang sama dalam Jadual Berkala Unsur.
i. State the group for the elements.
Nyatakan kumpulan bagi unsur itu.
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(1 mark)
ii. Give one reason for your answer in 1(a)(i).
Berikan satu sebab bagi jawapan anda di 1(a)(i).
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(1 mark)
iii. Q is located between T and R of the same group in the Periodic Table of Elements.
Write the electron arrangement for the atom of Q.
Q berada di antara T dan R dalam kumpulan yang sama dalam Jadual Berkala Unsur.
Tulis susunan elektron bagi atom Q.
(1 mark)
b) Explain why element R is more reactive than element Q.
Terangkan mengapa unsur R adalah lebih reaktif daripada unsur Q.
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(3 marks)
c) 0.1 mol of element T reacts with excess oxygen gas.
0.1 mol unsur T bertindak balas dengan gas oksigen berlebihan.
i. Write a balanced chemical equation for the reaction.
Tulis persamaan kimia seimbang bagi tindak balas itu.
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(2 marks)
ii. Calculate the mass of the product formed. [Relative atomic mass: T = 7, O = 16]
Hitung jisim hasil tindak balas yang terbentuk. [Jisim atom relatif: T = 7, O = 16]
(2 marks)
2. Table below shows the chemical formulae, melting points and boiling points of carbon dioxide
and magnesium.
Jadual di bawah menunjukkan formula kimia, takat lebur dan takat didih bagi karbon dioksida
dan magnesium.
Substance
Bahan
Chemical formulae
Formula kimia
Melting point (°C)
Takat lebur (°C)
Boiling point (°C)
Takat didih (°C)
Carbon dioxide
Karbon dioksida
CO2
–56.6
–78.5
Magnesium
Magnesium
Mg
650.0
1091.0
a) Referring to the table above,
Merujuk kepada jadual di atas,
i. State the type of particle in carbon dioxide.
Nyatakan jenis zarah bagi karbon dioksida.
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(1 mark)
ii. What is the physical state of magnesium at 700°C?
Apakah keadaan fizik bagi magnesium pada 700°C?
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(1 mark)
iii. Draw the arrangement of particles of magnesium in 2(a)(ii)
Lukiskan susunan zarah bagi magnesium di 2(a)(ii).
(1 mark)
b) Diagram below shows part of the Periodic Table of Elements. The letters P and Q do not
represent the actual symbols of the elements.
Rajah di bawah menunjukkan sebahagian daripada Jadual Berkala Unsur. Huruf P dan Q
tidak mewakili simbol sebenar unsur-unsur berkenaan.
P
Q
The table shows a characteristic for atoms of elements W and Z.
Jadual menunjukkan satu ciri bagi atom unsur W dan Z.
Atom
Atom
Characteristic
Ciri
W
Has electron arrangement of 2.8.8.1
Mempunyai susunan elektron 2.8.8.1
Z
Has a stable duplet electron arrangement.
Mempunyai susunan elektron duplet yang stabil
By referring to the table above, determine the position of element W and Z in the Periodic
Table of Elements in the diagram above.
Dengan merujuk jadual di atas, tentukan kedudukan unsur W dan Z dalam Jadual Berkala
Unsur di atas.
(2 marks)
3. The table below shows the elements in Period 3 with their respective proton numbers. The
letters do not represent the actual symbols of the elements.
Jadual di bawah menunjukkan unsur-unsur dalam Kala 3 dengan nombor proton masingmasing. Huruf di bawah tidak mewakili simbol sebenar bagi unsur-unsur tersebut.
Elements
Unsur
Proton number
Nombor proton
P
Q
R
S
T
U
V
W
11
12
13
14
15
16
17
18
a) Choose one element that is a noble gas.
Pilih satu unsur yang merupakan gas adi.
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(1 mark)
b) Explain your answer in 3(a).
Terangkan jawapan anda di 3(a).
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(1 mark)
c) Which element reacts vigorously with water to form hydrogen gas and change the red
litmus paper to blue?
Unsur yang manakah bertindak balas cergas dengan air untuk membentuk gas hidrogen
dan menukarkan kertas litmus merah kepada biru?
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(1 mark)
d) Write a balanced chemical equation for the reaction in 3(c).
Tulis persamaan kimia seimbang bagi tindak balas di 3(c).
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(2 marks)
e) How does the atomic size changes when going across the period from left to right? Explain.
Bagaimanakah saiz atom berubah apabila merentasi kala dari kiri ke kanan? Terangkan.
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(3 marks)
4. The diagram shows a part of the Periodic Table of Elements. W, X, Y and Z are not the actual
symbols of the elements.
Rajah menunjukkan sebahagian daripada Jadual Berkala Unsur. W, X, Y dan Z bukan simbol
sebenar unsur tersebut.
W
X
Y
Z
a) Based on the diagram above,
Berdasarkan rajah di atas,
i. Write an electron arrangement of atom W.
Tuliskan susunan elektron bagi atom W.
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(1 mark)
ii. Explain why atom W is chemically inert.
Terangkan mengapa atom W lengai secara kimia.
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(1 mark)
b) Which of the element is a halogen?
Unsur manakah adalah halogen?
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(1 mark)
c) Diagram shows the special characteristics of an element.
Rajah menunjukkan ciri-ciri istimewa bagi suatu unsur.
Can form complex ion
Boleh membentuk ion kompleks
Have more than one oxidation number
Mempunyai lebih daripada satu nombor pengoksidaan
Which element shows the above characteristics?
Unsur manakah menunjukkan ciri-ciri di atas?
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(1 mark)
d) When a small piece of element X is put in water, alkaline solution is formed and hydrogen
gas is released.
Apabila satu ketulan kecil unsur X dimasukkan ke dalam air, larutan beralkali terhasil dan
gas hidrogen terbebas.
i. Write a chemical equation for this reaction.
Tuliskan persamaan kimia bagi tindak balas ini.
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(1 mark)
ii. If 2.0 mol of X react with water, calculate the volume of gas released at room condition.
[The molar volume of gas is 24 dm3 mol-1 at room condition]
Jika 2.0 mol X bertindak balas dengan air, hitungkan isi padu gas yang terbebas pada
keadaan bilik. [Isi padu molar bagi gas ialah 24 dm3 mol-1 pada keadaan bilik]
(2 marks)
e) Element R is located below element X in the diagram above. Compare the reactivity of
element R and element X when react with water.
Unsur R berada di bawah unsur X dalam rajah di atas. Bandingkan kereaktifan unsur R
dan unsur X apabila bertindak balas dengan air.
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(1 mark)
5. The table below shows the electron arrangement of element X and element Y.
Jadual di bawah menunjukkan susunan elektron bagi unsur X dan unsur Y.
Element
Unsur
Electron arrangement
Susunan elektron
X
2.8.1
Y
2.8.8.1
a) State one physical property of both element X and Y.
Nyatakan satu sifat fizik bagi kedua-dua unsur X dan Y.
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(1 mark)
b) Does element X show similar chemical properties as element Y? Give a reason.
Adakah unsur X menunjukkan sifat kimia yang sama seperti unsur Y? Berikan satu sebab.
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(2 marks)
c) The diagram below shows the set-up of apparatus to compare the reactivity of element X
and element Y towards oxygen.
Rajah di bawah menunjukkan satu susunan radas bagi satu eksperimen untuk
membandingkan kereaktifan unsur X dan unsur Y terhadap oksigen.
i. State one observation when element X or element Y is burnt in the oxygen.
Nyatakan satu pemerhatian apabila unsur X atau unsur Y dibakar dalam oksigen.
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(1 mark)
ii. Compare the reactivity of element X and element Y towards oxygen.
Bandingkan kereaktifan bagi unsur X dan unsur Y terhadap oksigen.
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(1 mark)
iii. Explain your answer in 4(c)(ii).
Terangkan jawapan anda di 4(c)(ii).
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(3 marks)
iv. The product formed in the reaction between element X and oxygen is dissolved in
water. Write a balanced chemical equation for the reaction.
Hasil yang terbentuk dalam tindak balas antara unsur X dan oksigen dilarutkan di
dalam air. Tulis satu persamaan kimia seimbang bagi tindak balas tersebut.
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(2 marks)