Physics · Chemistry
Radioactivity and Nuclear Physics
519 Questions
Radioactivity and nuclear physics encompass the study of radioactive decay processes, neutron to proton ratios, and nuclear medicine. Questions cover various detection mechanisms, including scintillation counters and neutrino telescopes. These concepts are frequently tested in advanced science and civil services examinations.
Radioactive decayNuclear medicineParticle detectionNeutrino telescopesCosmic ray detection
Radioactivity and Nuclear Physics Questions
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Moleculear bond strength
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Radioactivity
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Moleculear reaction
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Isotopes
B
Correct answer
Explanation
Curie is a unit of radioactivity (specifically, activity of radioactive sources), measuring the number of nuclear decays per second. It quantifies how radioactive a substance is, not bond strength, reaction rates, or isotope counting.
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Dirty Bomb
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Gammator
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Salt Bomb
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Thermonuclear Bomb
A
Correct answer
Explanation
A dirty bomb (radiological dispersal device) combines radioactive material with conventional explosives to spread contamination. Unlike nuclear bombs, it doesn't involve nuclear fission or fusion. Gammator is not a recognized weapon, and salt/thermonuclear bombs are different categories.
C
Correct answer
Explanation
Uranium's chemical symbol is U, a single-letter symbol. Ua and Ur are not valid element symbols. Tm is thulium. Uranium is a radioactive actinide element used as nuclear fuel.
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Plutonium – 239
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Neptunium – 239
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Uranium – 235
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Uranium – 238
C
Correct answer
Explanation
The 'Little Boy' bomb dropped on Hiroshima on August 6, 1945, used Uranium-235 as its fissile material. The Nagasaki bomb 'Fat Man' used Plutonium-239. Uranium-238 is not fissile enough for weapons without enrichment.
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Uranium – 235
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Plutonium – 239
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Uranium – 238
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Neptunium – 239
B
Correct answer
Explanation
The Nagasaki bomb, codenamed 'Fat Man', used plutonium-239 as its fissile material. This was different from the Hiroshima bomb 'Little Boy', which used uranium-235. Plutonium-239 is produced in nuclear reactors by irradiating uranium-238, then through chemical separation.
C
Correct answer
Explanation
Plutonium is a radioactive element with atomic number 94, and its chemical symbol is 'Pu'. Promethium is 'Pm', Praseodymium is 'Pr', and Platinum is 'Pt'. Plutonium was named after the dwarf planet Pluto.
C
Correct answer
Explanation
Rb is the chemical symbol for Rubidium, an alkali metal with atomic number 37. Re is Rhenium, Ra is Radium, and Rf is Rutherfordium.
D
Correct answer
Explanation
Alpha particle emission involves losing 2 protons and 2 neutrons. Since atomic number equals proton count, losing 2 protons reduces the atomic number by 2. Radium (88) loses 2 protons, becoming radon (86).
A
Correct answer
Explanation
Alpha radiation consists of helium nuclei (2 protons + 2 neutrons) emitted during radioactive decay. When a nucleus emits an alpha particle, it loses 2 protons and 2 neutrons. Beta particles are electrons, gamma rays are electromagnetic waves, and 'delta' is not a type of radiation.
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lead
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graphite
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aluminium
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glass
A
Correct answer
Explanation
Lead is the best material for storing gamma radioactive substances because it has high density and atomic number, making it an excellent shield against gamma radiation. Graphite, aluminium, and glass offer minimal protection against gamma rays.
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a radioactive substance
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chemiluminescence process
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a photoelectric process
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burning of phosphorus
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Marie Curie
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Andre-Louis Debierne
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Rutherford
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Marie
A
Correct answer
Explanation
Marie Curie, along with her husband Pierre, discovered radium in 1898 through their pioneering work on radioactivity and pitchblende.
D
Correct answer
Explanation
Radon's chemical symbol is Rn, following the standard pattern of taking the first two letters from the element's name. Rd, Ra (radium), and R are not valid symbols for radon. Noble gases like radon typically use this straightforward naming convention.
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Roentgenium
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Rogernium
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Rutherfordium
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Silver
A
Correct answer
Explanation
Rg is roentgenium, named after Wilhelm Roentgen who discovered X-rays. 'Rogernium' is fictional, and Rutherfordium is Rf. Silver is Ag. Roentgenium is a synthetic transition metal in the same group as copper, silver, and gold.