Free Radioactive Decay MCQs with Answers
82 Radioactive Decay MCQs from Physics, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Radioactive decay is the spontaneous transformation of unstable nuclei, described by decay constant, activity, half life and the exponential decay law. Work includes alpha, beta and gamma emissions, decay equations and remaining nuclei, with half life distinguished from the time required for complete decay.
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- A. Beta
- B. Gamma
- C. He-Ne laser
- D. None of these
Explanation: Among the three types of common radiation, alpha particles have the highest ionization power.Alpha particles are composed of two protons…
Correct answer: None of these- A. mineral
- B. chemical
- C. radioactive
- D. all of these
Explanation: One of the most widely known radiometric dating techniques, radiocarbon dating measures the decay of the radioactive isotope Carbon-14…
Correct answer: radioactive- A. Gain energy
- B. Lose energy
- C. Lose protons
- D. Gain protons
Explanation: Radioactive decay results when an element changes to another element by changes within the atom's nucleus.
Correct answer: Lose energy- A. Electrons
- B. Protons
- C. Photons
- D. Neutrons
Explanation: The explanation is given below: Gamma (γ) radiation consists of high-energy photons, which are particles of electromagnetic radiation.
Correct answer: Photons- A. Increase by 3
- B. Increase by 5
- C. Decrease by 3
- D. Decrease by 5
Explanation: When W emitts beta radiations, it results in increase of +1 in atomic charge .Further when X emitts alpha radiation it results in decrease…
Correct answer: Decrease by 3- A. After one-minute
- B. After any time
- C. After two minutes
- D. After 1/2 minute
Explanation: Radioactive decay is a spontaneous phenomenon. It can decay anytime.
Correct answer: After any time- A. An atomic electron is ejected
- B. An electron which already present with in the nucleus is ejected
- C. A neutron in the nucleus decays emitting an electron
- D. A part of binding energy of nuclei is converted into electron
Explanation: When ratio of neutrons to protons is more than one, then neutrons convert into protons by emitting an electron.
Correct answer: A neutron in the nucleus decays emitting an electron- A. Decreases
- B. Increases
- C. Remains the same
- D. None of the above
Explanation: Option B is correct because when a radioactive nucleus emits a beta particle, the proton-neutron ratio increases because the mass number…
Correct answer: Increases- A. An α-particle has charge +4e
- B. When α particle travel through air, they cause ionization
- C. When α-particle travel through a sheet of gold foil, they can not make the gold radioactive
- D. None of the above
Explanation: Option B is correct because alpha particles have high ionization power but low penetrating power.
Correct answer: When α particle travel through air, they cause ionization- A. Option A
- B. Option B
- C. Option C
- D. Option D
Explanation: Option D is correct because during the decay of a neptunium nucleus with the emission of a β-particle and γ-radiation, the proton number…
Correct answer: Option D- A. Beta particles
- B. Gamma particles
- C. Alpha particles
- D. X-rays
Explanation: Option A is correct because the transformation of a neutron into a proton in the nucleus gives rise to the emission of a beta (β)…
Correct answer: Beta particles- A. 1st orbit
- B. Nucleus
- C. 2nd orbit
- D. Valence Shell
Explanation: Option B is correct because the electron (e^-) is emitted from the parent nucleus 234Th92 during the process of radioactive decay.
Correct answer: Nucleus33. According to the equation AZ X → Y + 3 α particles, what are the atomic and mass numbers of 'Y'?
- A. Z - 6, A - 12
- B. Z + 1, A
- C. Z - 2, A - 4
- D. Z + 3, A
Explanation: Option A is correct because the equation shows that 3 alpha particles are emitted from the nucleus.
Correct answer: Z - 6, A - 12- A. n1 = 8, n2 = 8
- B. n1 = 8, n2 = 6
- C. n1 = 6, n2 = 6
- D. n1 = 6, n2 = 8
Explanation: The radioactive decay series you've described involves the transformation of uranium-238 (^238U) into lead-206 (^206Pb) through a sequence…
Correct answer: n1 = 8, n2 = 6- A. γ-rays
- B. α-particles
- C. β-rays
- D. X-rays
Explanation: Option A is correct because alpha particles have high ionization power but low penetrating power.
Correct answer: γ-rays- A. Decrease as the age of atoms increase
- B. Increase as the age of atoms increase
- C. Is independent of the age
- D. Depends on the nature of activity
Explanation: The decay constant is a property of the radioactive material itself, and it does not change over time.
Correct answer: Is independent of the age- A. 90/144
- B. 91/144
- C. 91/143
- D. 90/143
Explanation: Proton number of Thorium = 90 Neutron number of Thorium = 243 - 90 = 143 β-particle =-1β0 After the emission of β particle: Proton number…
Correct answer: 91/143- A. Alpha
- B. Gamma
- C. Beta
- D. Cathode rays
Explanation: Gamma rays are electromagnetic waves and are neutral. The presence of an electric field does not affect their path of motion and they…
Correct answer: Gamma- A. α
- B. γ
- C. β
- D. Neutron
Explanation: The explanation is given below: In the context of nuclear physics, when a nucleus emits radiation without any change in its mass number…
Correct answer: γ- A. α
- B. γ
- C. β
- D. 1 α and 2 β
Explanation: The explanation is given below: When an atom emits radiation, and the daughter nucleus is an isotope of the parent nucleus, this typically…
Correct answer: 1 α and 2 β