Page 309 - MODUL SPEKTRUM FIZIK SPM

RADIOACTIVITY / KERADIOAKTIFAN

1. (a) Process of disintegration of unstable nucleus to become a more stable nucleus.
Proses penguraian nukleus tidak stabil untuk menjadi nukleus yang lebih stabil.
(b) GM tube / Tiub GM
(c) (i) K
(ii) T ½ = 4 minutes
(d) 20 minutes = 5  4 minutes = 5 half life

 Rate of decay of K is 6.25 counts per minute after 20 minutes.
Kadar reputan K ialah 6.25 bilangan per minit selepas 20 minit.

2. (a) Fast moving electron / Electron berhalaju tinggi
(b) (i)

(ii) Beta particles has negative charge / attracted to the positive plate
Zarah beta mempunyai cas negatif / tertarik kepada plat positif
(iii)Increases / Bertambah

3. (a) Nuclear fusion happens in the Sun
Two smaller nuclei, deuterium and tritium combine.
One larger nucleus, helium is formed and a neutron is released.
Some mass (mass defect) is converted into energy and released.

(b) Mass defect, m = (2.014102 + 3.016050) – (4.002603 + 1.008665)
= 0.018884 a.m.u
= 0.018884  1.66 X 10 –27 kg
= 3.13  10 –29 kg
2
E = mc
8 2
= (3.13  10 –29 kg)(3  10 )
= 2.82  10 –12 J

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