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Ch.21 - Nuclear Chemistry
Chapter 21, Problem 34

It has been suggested that strontium-90 (generated by nuclear testing) deposited in the hot desert will undergo radioactive decay more rapidly because it will be exposed to much higher average temperatures. (a) Is this a reasonable suggestion? (Section 14.5) (b) Does the process of radioactive decay have an activation energy, like the Arrhenius behavior of many chemical reactions (Section 14.5)?

Verified step by step guidance
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Step 1: Understand the nature of radioactive decay. Radioactive decay is a nuclear process where an unstable atomic nucleus loses energy by emitting radiation. This process is not influenced by external factors such as temperature, pressure, or chemical state.
Step 2: Consider the suggestion that higher temperatures might affect the rate of radioactive decay. In chemical reactions, higher temperatures can increase reaction rates due to increased molecular motion and collision frequency. However, radioactive decay is a nuclear process, not a chemical one.
Step 3: Evaluate the concept of activation energy in the context of radioactive decay. Activation energy is a term used in chemical kinetics to describe the minimum energy required for a reaction to occur. Radioactive decay does not require activation energy because it is a spontaneous process governed by the stability of the nucleus.
Step 4: Compare radioactive decay to chemical reactions. Chemical reactions often follow the Arrhenius equation, which shows that reaction rates increase with temperature due to activation energy. Radioactive decay, however, is not affected by temperature changes because it does not involve breaking or forming chemical bonds.
Step 5: Conclude whether the suggestion is reasonable. Given that radioactive decay is a nuclear process unaffected by temperature, the suggestion that strontium-90 will decay more rapidly in a hot desert due to higher temperatures is not reasonable. The decay rate is determined by the isotope's half-life, which is constant regardless of environmental conditions.

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Radioactive Decay

Radioactive decay is a spontaneous process by which unstable atomic nuclei lose energy by emitting radiation. This process occurs at a characteristic rate for each isotope, defined by its half-life, which is the time required for half of the radioactive atoms in a sample to decay. Temperature does not significantly affect the rate of decay, making the suggestion that higher temperatures would increase decay rates unreasonable.
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Half-Life

The half-life of a radioactive isotope is the time it takes for half of the original amount of the substance to decay into its daughter products. This concept is crucial for understanding the stability and longevity of radioactive materials. For strontium-90, the half-life is approximately 28.8 years, indicating that its decay is a time-dependent process rather than one influenced by external temperature conditions.
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Activation Energy in Radioactive Decay

Activation energy is the minimum energy required for a chemical reaction to occur, often associated with the Arrhenius equation in chemical kinetics. However, radioactive decay does not have an activation energy in the same sense as chemical reactions; it is a nuclear process that occurs independently of temperature and does not require energy input to proceed. Thus, the decay rate remains constant regardless of environmental conditions.
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