Page 51 - Hybrid PBD 2022 Tg 4 - Kimia

Kimia Tingkatan 4 Bab 2
3. Apakah maksud kelimpahan semula jadi? SP 2.4.2 TP1
What is the meaning of natural abundance?
Kelimpahan semula jadi ialah peratusan isotop yang wujud dalam suatu sampel semula jadi unsur itu .

Natural abundance is the percentage of isotopes present in a natural sample of the element .
26
25
24
4. Magnesium wujud secara semula jadi dalam tiga isotop iaitu 79.0 % Mg, 10.0% Mg dan 11.0% Mg. Hitung
12
12
12
jisim atom relatif bagi magnesium. SP 2.4.2 TP3
26
25
24
Magnesium exists naturally in three isotopes which are 9.0% Mg, 10.0% Mg and 11.0% Mg. Calculate the relative atomic mass of
12
12
12
magnesium.
Penerbitan Pelangi Sdn Bhd. All Rights Reserved
Σ (% isotop × jisim isotop)
Jisim atom relatif / Relative atomic mass = Σ (% isotope x isotope mass)
100
(79.0 × 24) + (10.0 × 25) + (11.0 × 26)
=
100
(1896) + (250) + (286)
=
100
= 24.32
5. Padankan isotop dengan kegunaannya. SP 2.4.3 TP1
Match the isotopes with their uses.
(a) Natrium-24
Sodium-24

(b) Uranium -235
Uranium-235

(c) Kobalt-60
Cobalt-60

(d) Karbon-14
Carbon-14

(e) Iodin-131
Iodine-131

29 © Penerbitan Pelangi Sdn. Bhd.

02 Bab 2.indd 29 10/29/21 5:13 PM