Page 5 - Modul A+ Kimia Tg 4_Pan Asia Publications

Contoh/Example 1
Berapa kalikah 2 atom bromin lebih besar daripada 5 atom oksigen?
How many times greater are 2 bromine atoms compared to 5 oxygen atoms?
[JAR/ RAM: Br = 80; O = 16]

Penyelesaian/Solution :
Jisim 2 atom bromin = Q kali lebih besar daripada jisim 5 atom oksigen
Mass of 2 bromine atom Q times greater than the mass of 5 oxygen atoms
2 (80) = Q  5 (16)
160
80 = Q
Q = 2
∴ 2 atom bromin ialah 2 kali lebih besar daripada 5 atom oksigen.
©PAN ASIA PUBLICATIONS
2 bromine atoms are 2 times greater than 5 oxygen atoms.

Contoh/Example 2 TP 3
Berapakah atom oksigen yang mempunyai jisim sama dengan satu atom sulfur?
How many oxygen atoms that have the same mass as one atom of sulphur?
[JAR/ RAM: S = 32; O = 16]

Penyelesaian/Solution :
Jisim Q atom oksigen = Jisim satu atom sulfur
Mass of Q atoms oxygen Mass of one atom sulphur
Q(16) = 1(32)
Q = 2
Bilangan atom oksigen/ Number of oxygen atoms = 2

Contoh/Example 3 TP 3

Jisim bagi 4 atom unsur X adalah sama dengan jisim bagi 5 atom oksigen. X bukan simbol sebenar bagi unsur itu. Berapakah
jisim atom relatif, JAR bagi unsur X?
The mass of 4 atoms of element X is equal to the mass of 5 oxygen atoms. X is not the actual symbol of the element. What is the relative
atomic mass, RAM of element X?
[JAR/ RAM: O = 16]

Penyelesaian/Solution :
Jisim 4 atom unsur X = Jisim 5 atom oksigen
Mass of 4 atoms element X Mass of 5 oxygen atoms
4(Q) = 5(16)
Q = 20
∴ Jisim atom relatif, JAR bagi unsur X/ Relative atomic mass, RAM of element X = 20
r

B Jisim molekul relatif, JMR dan jisim formula relatif, JFR
Relative molecular mass, RMM and relative formula mass, RFM
1. Jisim molekul relatif, JMR sesuatu molekul ditakrif sebagai jisim purata molekul itu apabila dibandingkan
1
dengan kali jisim satu atom karbon-12 .
12 1
Relative molecular mass, RMM of a molecule is defined as the average mass of the molecule when compared with 12
times the mass of one carbon-12 atom .

Jisim purata satu molekul
Jisim molekul relatif, JMR =
1 × jisim satu atom karbon-12
12
Average mass of one molecule
Relative molecular mass, RMM =
1
12 × mass of one atom of carbon-12

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