Assertion (A) : The isotopes are the atoms of the same element with di...
A is false but R is true
Explanation: The isotopes are indeed atoms of the same element with different atomic masses due to different numbers of neutrons. However, they do not require different positions in the periodic table. Isotopes of the same element share the same chemical properties and thus occupy the same position in the periodic table. The atomic number, which determines an element's place in the periodic table, remains the same for all isotopes of a given element.
Assertion (A) : The isotopes are the atoms of the same element with di...
Assertion (A): The isotopes are the atoms of the same element with different atomic masses. They require different positions in the periodic table.
Reason (R): Variable number of neutrons in the nuclei of the atoms of the same elements leads to different atomic masses.
Explanation:
Isotopes refer to atoms of the same element that have different atomic masses. These isotopes have the same number of protons but different numbers of neutrons in their nuclei. Therefore, the reason for their different atomic masses is the variable number of neutrons present in their nuclei.
The atomic mass of an element is determined by the sum of the masses of its protons, neutrons, and electrons. Since isotopes have different numbers of neutrons, their total mass will vary, leading to different atomic masses.
Rebuttal:
The assertion states that isotopes require different positions in the periodic table. However, this is not true. The periodic table is organized based on the atomic number of elements, which is the number of protons in their nuclei. Isotopes of the same element have the same number of protons, so they are placed in the same position in the periodic table.
Conclusion:
Therefore, assertion (A) is false as isotopes of the same element have different atomic masses due to a variable number of neutrons, but they do not require different positions in the periodic table. The reason (R) is true as the variable number of neutrons leads to different atomic masses. Hence, the correct answer is option 'D'.
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