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MODUL • Fizik TINGKATAN 5

4 Pembilang bunga api / Sparks counter • Sumber radioaktif didekatkan kepada kasa dawai.
The radioactive source is brought near to the wire gauze.
• Sinar radioaktif mengionkan molekul-molekul udara.
Sumber radioaktif The radioactive radiation ionises the air molecules.
Radioactive source • Penyahcasan ion-ion molekul udara di katod dan anod akan
menghasilkan percikan bunga api.
Kasa dawai The discharge of ions of air molecules at the cathode and the
Wire gauze anode will generate sparks.
• Sesuai digunakan untuk mengesan sinar alfa kerana sinar alfa
2 mm mempunyai kuasa pengionan yang tinggi.
Voltan It is suitable to be used to detect alpha rays because the alpha
Wayar lampau
Wire tinggi rays have a high power of ionisation.
Extra
high
tension

5 Lencana Fotografik / Photographic badge
• Dipakai oleh individu yang menguruskan bahan radioaktif.
It is worn by person who manages radioactive materials.
• Bahagian filem yang terdedah kepada sinar radioaktif menjadi warna hitam.
The part of film which is exposed to radioactive rays will become black.
• Darjah kehitaman menunjukkan darjah pendedahan individu tersebut kepada sinaran radioaktif.
The degree of blackness indicates degree the individual exposed to the radioactive rays.

Reputan radioaktif / Radioactive decay

Alfa / Alpha Beta Gama / Gamma

ZX Z–2 Y 2He ZX Z+1Y –1e ZX ZY
A
A
4
A
A
A–4
0
A
• Nuklid anak mempunyai dua proton • Satu neutron bertukar menjadi satu • Pancaran sinar gama tidak mengubah
dan dua neutron kurang daripada nuklid proton baru dan satu elektron baru struktur nukleus atom, cuma
induk. sewaktu reputan beta. menjadikannya lebih stabil. UNIT 5
The daughter nuclides have two protons A neutron turns into a new proton and a The emission of gamma rays do not
and two neutrons less than the parent new electron during the beta decay. change the structure of the atomic
UNIT 5
nuclide. • n → p + e nucleus, it just make it more stable.
1
1
0
–1
1
0
• Nombor proton berkurang sebanyak • Proton baru kekal dalam nukleus • Biasanya sinar gama akan dipancarkan
dua dan nombor nukleon berkurang manakala elektron baru dipancarkan bersama dengan sinar alfa dan sinar
sebanyak empat. sebagai sinar beta beta.
The number of protons is reduced by two The new proton remains in the nucleus Usually gamma rays will be emitted with
and the number of nucleons is reduced while the new electron is emitted as beta alpha and beta rays.
by four. • Sewaktu pancaran alfa dan beta, tenaga
• Nukleus kehilangan satu neutron tetapi
mendapat satu proton. lebihan dibebaskan sebagai sinar gama.
During emission of alpha and beta, the
The nucleus loses one neutron but got excess energy is released as gamma rays
one proton.
• Nombor proton bertambah sebanyak
satu.
The proton number increases by one.
• Nombor nukleon tidak berubah.
The nucleon number is unchanged.

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