NET, IAS, State-SET (KSET, WBSET, MPSET, etc.), GATE, CUET, Olympiads etc.: Chemistry MCQs (Practice_Test 31 of 31)
Doorsteptutor material for competitive exams is prepared by world's top subject experts: get questions, notes, tests, video lectures and more- for all subjects of your exam.
- The carbon-14 activity of some ancient Peruvian corn was found to be 10 disintegrations/minute/gram. If present-day plant life shows 15 disintegrations/minute/gram, how old is the Peruvian corn? The half-life of carbon-14 is 5,730 years.
- 1,455 years
- 1,910 years
- 3,350 years
- 3,820 years
- 9,080 years
- Which type of nuclear process requires a temperature of over a million degrees?
- beta particle production
- fission reaction
- alpha particle emission
- fusion reaction
- positron production
- In passing through matter, alpha particles lose energy and damage tissues by producing:
- neutrons.
- gamma rays.
- radiation.
- beta particles.
- ions.
- It is well-known that uranium isotopes can undergo fission reactions and that hydrogen isotopes can undergo fusion reactions. These reactions are examples of a drive toward:
- equilibrium.
- thermodynamic stability.
- negative S.
- kinetic stability.
- positive G.
- Which of the following balanced equations indicates a FUSION reaction?
- bismuth-209 + helium-4 ⇾ astatine-211 + 2 neutrons
- helium-2 + hydrogen-2 ⇾ hydrogen-3 + hydrogen-1
- plutonium-239 + neutron ⇾ americium-240 + beta particle
- uranium-239 ⇾ neptunium-239 + beta particle
- beryllium-7 + electron ⇾ lithium-7
- Which statement is FALSE?
- The larger the binding energy per nucleon, the more stable the nucleus.
- The alpha particle has a charge of 2 + .
- The mass of a nucleus is always less than the original mass of its constituent protons and neutrons.
- Alpha particle production is the only route by which unstable nuclei can spontaneously decay.
- Alpha particles are more massive than beta particles.
- Iron-49 decays by positron emission with a half-life of 0.08 seconds. What nuclide is produced in this decay process?
- manganese-49
- cobalt-49
- chromium-45
- iron-48
- None of these.
- The following are produced in radioactive decay processes. Which one has neither mass nor charge?
- alpha particles
- beta particles
- gamma rays
- positrons
- neutrons
- The function of the CONTROL RODS in a nuclear power plant is to:
- slow the neutrons down so that they can cause fission.
- absorb the heat produced so that it can be carried to an external turbine.
- absorb neutrons to control the amount of fission that is occuring.
- provide the fuel needed for fission to occur.
- None of the above:
- Smoke detectors contain a small amount of americium-241. What is the final product nuclide if americium-241 radioactively decays by a total of eight alpha decays and four beta decays?
- rhenium-209
- gold-209
- bismuth-209
- plutonium-237
- americium-225