10 questions · Form 5 Physics Bab 6: Nuclear Physics
Which particle is emitted when a neutron inside an unstable nucleus transforms into a proton during radioactive decay?
Prefer reading to quizzing? All 10 questions are listed below with the answer and explanation under each one.
1. Which particle is emitted when a neutron inside an unstable nucleus transforms into a proton during radioactive decay?
Answer: B
In beta decay, a neutron breaks down into a proton and a high-speed electron (beta particle).
2. Which statement correctly describes the term 'spontaneous decay' in radioactivity?
Answer: B
Spontaneous decay happens naturally and is totally unaffected by physical or chemical conditions.
3. Nuclear fusion requires extremely high temperatures primarily to:
Answer: B
Positively charged nuclei strongly repel each other. Extremely high thermal kinetic energy is required to force them close enough together to fuse.
4. Which sheet material is sufficient to completely stop alpha particles?
Answer: A
Alpha particles have low penetrating power and are absorbed by a thin sheet of paper.
5. Which of the following radioactive emissions possesses the strongest ionizing power?
Answer: A
Alpha particles (+2 charge, largest mass) have the highest power to ionize surrounding gas molecules.
6. Which equation correctly represents a nuclear fission reaction?
Answer: C
Uranium-235 absorbing a neutron and splitting into Barium-141, Krypton-92, extra neutrons, and energy is a nuclear fission reaction.
7. When a Radon-222 nucleus ($^{222}_{86}Rn$) emits an alpha particle, what is the nucleon number and proton number of the daughter nucleus formed?
Answer: A
Alpha emission removes 4 from nucleon number (222 - 4 = 218) and 2 from proton number (86 - 2 = 84).
8. An unstable isotope Carbon-14 ($^{14}_{6}C$) decays into Nitrogen-14 ($^{14}_{7}N$). What type of decay occurred?
Answer: B
Proton number increases by 1 (6 to 7) while nucleon number remains 14. This signifies beta emission ($^{0}_{-1}e$).
9. Which of the following processes is the main source of thermal and radiant energy produced by the Sun?
Answer: B
The Sun generates energy by fusing Hydrogen isotopes (Deuterium and Tritium) into Helium nuclei under massive gravitational pressure and heat.
10. Calculate the energy released when a nuclear reaction produces a mass defect of 3.2 × 10⁻²⁸ kg. (c = 3.0 × 10⁸ m s⁻¹)
Answer: A
E = Δm × c² = (3.2 × 10⁻²⁸ kg) × (3.0 × 10⁸ m s⁻¹)² = 2.88 × 10⁻¹¹ J.