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Which of the following pairs is/are correctly matched?
1. Isotopes : Atoms with same atomic number but different atomic mass.
2. Isobars : Atoms with same number of neutrons but different atomic number.
3. Isotones : Atoms with same mass number but different atomic number.

Q. Select the correct answer using the codes given below :
  • a)
    1, 2 and 3
  • b)
    1 only
  • c)
    1 and 2 only
  • d)
    2 only
Correct answer is option 'B'. Can you explain this answer?
Verified Answer
Which of the following pairs is/are correctly matched?1. Isotopes : At...
Isotopes are variants of a particular chemical element: while all isotopes of a given element share the same number of protons and electrons, each isotope differs from the others in its number of neutrons. For example, carbon-12, carbon-13 and carbon-14 are three isotopes of the element carbon with mass numbers 12, 13 and 14 respectively. The atomic number of carbon is 6, which means that every carbon atom has 6 protons, so that the neutron numbers of these isotopes are 6, 7 and 8 respectively
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Which of the following pairs is/are correctly matched?1. Isotopes : At...
Isotopes, Isobars, and Isotones

Isotopes, Isobars, and Isotones are terms used in the study of atomic structure. Let's understand each of them in detail.

Isotopes
Isotopes are atoms that have the same atomic number but different atomic mass. They have the same number of protons in the nucleus but different numbers of neutrons. For example, carbon-12 and carbon-14 are isotopes of carbon. Carbon-12 has 6 protons and 6 neutrons, while carbon-14 has 6 protons and 8 neutrons.

Isobars
Isobars are atoms that have the same mass number but different atomic numbers. They have the same total number of nucleons (protons + neutrons) in the nucleus but different numbers of protons and neutrons. For example, carbon-14 and nitrogen-14 are isobars. Carbon-14 has 6 protons and 8 neutrons, while nitrogen-14 has 7 protons and 7 neutrons.

Isotones
Isotones are atoms that have the same number of neutrons but different atomic numbers and atomic masses. They have the same neutron number but different proton numbers and different mass numbers. For example, carbon-12 and boron-13 are isotones. Carbon-12 has 6 protons and 6 neutrons, while boron-13 has 5 protons and 8 neutrons.

Answer:
The correct option is B, i.e., 1 only. Isotopes are atoms with the same atomic number but different atomic masses. Isobars are atoms with the same mass number but different atomic numbers. Isotones are atoms with the same number of neutrons but different atomic numbers and atomic masses.
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Milankovitch proposed in the early twentieth century that the ice ages were caused by variations in the Earth’s orbit around the Sun. For some time, this theory was considered untestable, largely because there was no sufficiently precise chronology of the ice ages with which the orbital variations could be matched. To establish such a chronology, it is necessary to determine the relative amounts of land ice that existed at various times in the Earth’s past. A recent discovery makes such a determination possible: relative land-ice volume for a given period can be deduced from the ratio of two oxygen isotopes, 16 and 18, found in ocean sediments. Almost all the oxygen in water is oxygen 16, but a few molecules out of every thousand incorporate the heavier isotope 18.When an ice age begins, the continental ice sheets grow, steadily reducing the amount of water evaporated from the ocean that will eventually return to it. Because heavier isotopes tend to be left behind when water evaporates from the ocean surfaces, the remaining ocean water becomes progressively enriched in oxygen 18. The degree of enrichment can be determined by analyzing ocean sediments of the period, because these sediments are composed of calcium carbonate shells of marine organisms, shells that were constructed with oxygen atoms drawn from the surrounding ocean. The higher the ratio of oxygen 18 to oxygen 16 in a sedimentary specimen, the more land ice there was when the sediment was laid down.It can be inferred from the passage that precipitation formed from evaporated ocean water has

Milankovitch proposed in the early twentieth century that the ice ages were caused by variations in the Earth’s orbit around the Sun. For some time, this theory was considered untestable, largely because there was no sufficiently precise chronology of the ice ages with which the orbital variations could be matched. To establish such a chronology, it is necessary to determine the relative amounts of land ice that existed at various times in the Earth’s past. A recent discovery makes such a determination possible: relative land-ice volume for a given period can be deduced from the ratio of two oxygen isotopes, 16 and 18, found in ocean sediments. Almost all the oxygen in water is oxygen 16, but a few molecules out of every thousand incorporate the heavier isotope 18.When an ice age begins, the continental ice sheets grow, steadily reducing the amount of water evaporated from the ocean that will eventually return to it. Because heavier isotopes tend to be left behind when water evaporates from the ocean surfaces, the remaining ocean water becomes progressively enriched in oxygen 18. The degree of enrichment can be determined by analyzing ocean sediments of the period, because these sediments are composed of calcium carbonate shells of marine organisms, shells that were constructed with oxygen atoms drawn from the surrounding ocean. The higher the ratio of oxygen 18 to oxygen 16 in a sedimentary specimen, the more land ice there was when the sediment was laid down.According to the passage, which of the following is true of the ratios of oxygen isotopes in ocean sediments?

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Which of the following pairs is/are correctly matched?1. Isotopes : Atoms with same atomic number but different atomic mass.2. Isobars : Atoms with same number of neutrons but different atomic number.3. Isotones : Atoms with same mass number but different atomic number.Q.Select the correct answer using the codes given below :a)1, 2 and 3b)1 onlyc)1 and 2 onlyd)2 onlyCorrect answer is option 'B'. Can you explain this answer?
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Which of the following pairs is/are correctly matched?1. Isotopes : Atoms with same atomic number but different atomic mass.2. Isobars : Atoms with same number of neutrons but different atomic number.3. Isotones : Atoms with same mass number but different atomic number.Q.Select the correct answer using the codes given below :a)1, 2 and 3b)1 onlyc)1 and 2 onlyd)2 onlyCorrect answer is option 'B'. Can you explain this answer? for UPSC 2024 is part of UPSC preparation. The Question and answers have been prepared according to the UPSC exam syllabus. Information about Which of the following pairs is/are correctly matched?1. Isotopes : Atoms with same atomic number but different atomic mass.2. Isobars : Atoms with same number of neutrons but different atomic number.3. Isotones : Atoms with same mass number but different atomic number.Q.Select the correct answer using the codes given below :a)1, 2 and 3b)1 onlyc)1 and 2 onlyd)2 onlyCorrect answer is option 'B'. Can you explain this answer? covers all topics & solutions for UPSC 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Which of the following pairs is/are correctly matched?1. Isotopes : Atoms with same atomic number but different atomic mass.2. Isobars : Atoms with same number of neutrons but different atomic number.3. Isotones : Atoms with same mass number but different atomic number.Q.Select the correct answer using the codes given below :a)1, 2 and 3b)1 onlyc)1 and 2 onlyd)2 onlyCorrect answer is option 'B'. Can you explain this answer?.
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