Select the correct answer.
For heavy elements, what is the ratio of neutrons to protons that predicts a stable nucleus?
A. 1:1
B. 1.5:1
C. 2:1
D. 10:5

The problem discusses the neutron-to-proton ratio in stable heavy nuclei.
Heavy elements need a higher neutron-to-proton ratio than lighter elements for stability.
The correct ratio for heavy elements is approximately 1.5:1.
Therefore, the answer is B. 1.5:1.

Explanation

Problem Analysis The question asks about the ratio of neutrons to protons in stable heavy nuclei. Heavier elements require a higher neutron-to-proton ratio for stability due to increased proton-proton repulsion. We need to select the option that reflects this trend.

Reasoning In stable light nuclei, the neutron-to-proton ratio is approximately 1:1. However, as the atomic number increases, the ratio increases to maintain stability. This is because the strong nuclear force needs to overcome the increasing electrostatic repulsion between protons.

Selecting the Correct Ratio For heavy elements, the neutron-to-proton ratio is greater than 1:1. Among the given options, 1.5:1 and 2:1 are greater than 1:1. The ratio 10:5 simplifies to 2:1. The most appropriate ratio for heavy elements is 1.5:1.

Final Answer Therefore, the correct answer is B. 1.5:1.


Examples
Understanding the neutron-to-proton ratio is crucial in nuclear medicine, particularly in the production of radioisotopes used for imaging and therapy. For instance, when creating isotopes for PET scans, adjusting the neutron-to-proton ratio ensures the radioisotope decays in a manner suitable for imaging, providing clear and accurate diagnostic information. This balance is also vital in radiation therapy, where unstable isotopes are designed to target and destroy cancerous cells while minimizing harm to healthy tissue. By controlling this ratio, we can optimize the effectiveness and safety of nuclear treatments.

Answered by GinnyAnswer | 2025-07-08

For heavy elements, the neutron-to-proton ratio that predicts a stable nucleus is approximately 1.5:1. Therefore, the correct option is B. 1.5:1.
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Answered by Anonymous | 2025-07-12