The instability of the nucleus of the atoms causes radioactivity. Radioactivity is the result of the decay of the nucleus. This process is dependent on the law of conservation of charge. The physical and chemical properties of the daughter nucleus are different from the mother nucleus.
Q1: The neutral atoms of all isotopes of the same element contain the same number of __________.
- neutrons only.
- Mass numbers
Answer: (b) Electrons
Q2: The atomic number is not changed by which type of radioactive decay?
- The atomic number is affected by all forms of radioactive decay
Answer: (c) Gamma
Q3: Isotopes of an element have a different number of
Answer: (b) Neutron
Q4: Three types of radioactive elements are emitted when unstable nuclei undergo radioactive decay. Which of the following is not one of them
Answer: (d) delta
Q5: A nuclear fission reaction becoming self-sustaining depends on
Answer: (b) Neutrons
Q6: Helium nuclei particles are called
- Gamma particles
- Beta particles
- Alpha particles
- No particles that are helium nuclei
Answer: (a) alpha particles
Q7: When two atomic nuclei combine it is called as
- Chain reaction
- Nuclear fusion
- Nuclear decay
- Nuclear fission
Answer: (b) Nuclear fusion
Q8: The number of protons or atomic number is reduced to 2 by which form of radioactive decay?
- Gamma decay
- Alpha decay
- None of the above
Answer: (c) Alpha decay
Q9: Which statement is true for all three types of radioactive emission?
- They are deflected by electric fields
- They ionise gases
- They are completely absorbed by a thin aluminium sheet
- They emit light
Answer: (b) They ionise gases
Q10: A nuclide of the element plutonium 94 Pu 242. What is the number of neutrons in its nucleus?
Answer: (c) 148