Test: Nuclear Physics - EmSAT Achieve MCQ

• Deuteron, nucleus of deuterium (heavy hydrogen) that consists of one proton and one neutron.
• Deuterons are formed chiefly by ionizing deuterium (stripping the single electron away from the atom) and are used as projectiles to produce nuclear reactions after accumulating high energies in particle accelerators.

• Graphite rods are used as a moderator.
• Moderator is a material used in a nuclear reactor to slow down the neutrons produced from fission. 
• By slowing the neutrons down the probability of neutron interacting with Uranium-235 nuclei is greatly increased thereby maintaining the chain reaction. 
• By inserting control rods between the fuel rods the chain reaction can be slowed down or shut down.
• Hence option 2 is the answer.

• ​Energy from the uranium atom:
  • The nucleus of the U-235 atom comprises 92 protons and 143 neutrons (92 + 143 = 235).
  • When the nucleus of a U-235 atom captures a moving neutron it splits in two (fissions) and releases some energy in the form of heat, also two or three additional neutrons are thrown off.
  • If enough of these expelled neutrons cause the nuclei of other U-235 atoms to split, releasing further neutrons, a fission 'chain reaction' can be achieved.
  • When this happens over and over again, many millions of times, a very large amount of heat is produced from a relatively small amount of uranium.

• From the above, it is clear that wood, gobar- gas, and coal are an example of a biomass energy source. Therefore option 1, 2, and 4 is not a bio-mass energy source.
• On the other hand, nuclear energy is obtained from nuclear fusion and fission. Therefore option 2 is the answer.

• Kudankulam Nuclear Power Plant is located 650 km south of Chennai, in the Tirunelveli district of Tamilnadu, India.
• The power plant will have a combined capacity of 6000 Mega Watt upon completion.
• The Atomic Energy Commission was established in 1948 by the efforts of Dr. Homi Jahangir Bhabha, the father of Atomic Energy Research in India.
• India's first atomic research reactor 'Apsara' started working in Trombay (near Mumbai) but India's first Nuclear Power reactor was established at Tarapur in 1969.
• Production of nuclear energy requires uranium, thorium, and heavy water, Uranium is found in Jharkhand, Rajasthan, and Meghalaya.

U₉₂²³⁸ → A₄₆¹¹⁹ + B₄₆¹¹⁹ 

• Since the U -238 is an unstable atomic nucleus. The nucleus having an even number of protons and neutrons then that nucleus will be stable.
• After splitting into two identical parts it produced two stable nuclei because both have an even number of protons and neutrons. Hence option 2 is correct.

• From above it is clear that the that an alpha particle consist of two proton and two neutrons and they are tightly bound.
• An alpha-particle is identical to the nucleus of a helium atom. Therefore option 1 is correct.

• Carbon-14 dating is a method of age determination that depends upon the decay to nitrogen of radiocarbon (carbon-14 isotope).
• Carbon-14 is continually formed in nature by the interaction of neutrons with nitrogen-14 in the Earth’s atmosphere; the neutrons required for this reaction are produced by cosmic rays interacting with the atmosphere.
• Radiocarbon present in molecules of atmospheric carbon dioxide enters the biological carbon cycle: It is absorbed from the air by green plants and then passed on to animals through the food chain.
• Radiocarbon decays slowly in a living organism, and the amount lost is continually replenished as long as the organism takes in air or food and once the organism dies, however, it ceases to absorb carbon-14, so that the amount of the radiocarbon in its tissues steadily decreases.
• Carbon-14 has a half-life of 5,730 ± 40 years i.e., half the amount of the radioisotope present at any given time will undergo spontaneous disintegration during the succeeding 5,730 years.
• Because carbon-14 decays at this constant rate, an estimate of the date at which an organism died can be made by measuring the amount of its residual radiocarbon.

• From the above, it is clear that nuclei having the same number of neutrons but a different mass number are called isotones. Therefore option 3 is correct.

• Charge of proton = +e
• From above it is clear that the charge on an alpha particle is +2e.
• That represents the α particles are 2 times the charge of proton