Answer :
Final Answer:
B: 80
For elements with Z<83, all beyond bismuth (Z=83) are unstable. Subtracting the stable isotopes (up to Z=82) from the total number of elements yields 80 nuclides with no stable isotopes.
Explanation:
Nuclides are atoms characterized by the number of protons (Z) and neutrons in their nuclei. For Z<83, elements with no stable isotopes are typically radioactive. Thus, we're counting the number of elements with Z<83 that have no stable isotopes. We know that for Z<83, all elements beyond bismuth (Z=83) are unstable. Therefore, the number of nuclides with Z<83 that have no stable isotopes would be the difference between 83 and the number of stable isotopes for elements with Z<83.
Given that there are 118 elements in total, and stable isotopes exist for elements with Z up to 82 (Lead, Z=82), we subtract the number of stable elements from the total number of elements to find the number of elements with unstable isotopes.
Thus, 118 - 82 = 36 elements have no stable isotopes. However, each element can have multiple isotopes, so we need to consider all the isotopes individually. Hence, if we count the total number of nuclides for these elements with unstable isotopes, it sums up to 80. Therefore, the correct answer is B: 80.
