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Ch.20 - Nuclear Chemistry
Chapter 20, Problem 38

Radioactive 100Tc decays to form 100Mo. There are two possible pathways for this decay. Write the balanced equations for both pathways.

Verified step by step guidance
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Step 1: Identify the initial and final isotopes involved in the decay process. The initial isotope is Technetium-100 (\(^{100}_{43}\text{Tc}\)) and the final isotope is Molybdenum-100 (\(^{100}_{42}\text{Mo}\)).
Step 2: Determine the possible decay pathways. Since \(^{100}_{43}\text{Tc}\) is decaying to \(^{100}_{42}\text{Mo}\), consider common decay modes such as beta decay and electron capture.
Step 3: Write the balanced equation for beta decay. In beta decay, a neutron in the nucleus is converted into a proton, emitting a beta particle (\(\beta^-\)) and an antineutrino (\(\bar{\nu}_e\)). The equation is: \(^{100}_{43}\text{Tc} \rightarrow ^{100}_{42}\text{Mo} + \beta^- + \bar{\nu}_e\).
Step 4: Write the balanced equation for electron capture. In electron capture, an inner orbital electron is captured by the nucleus, converting a proton into a neutron and emitting a neutrino (\(\nu_e\)). The equation is: \(^{100}_{43}\text{Tc} + e^- \rightarrow ^{100}_{42}\text{Mo} + \nu_e\).
Step 5: Verify that both equations are balanced in terms of mass number and atomic number. Ensure that the sum of mass numbers and atomic numbers on both sides of each equation are equal.

Key Concepts

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

Radioactive Decay

Radioactive decay is the process by which an unstable atomic nucleus loses energy by emitting radiation. This can occur through various pathways, including alpha decay, beta decay, and gamma decay. In the case of technetium-100 (100Tc), it transforms into a more stable isotope, molybdenum-100 (100Mo), through specific decay processes.
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Balanced Nuclear Equations

A balanced nuclear equation represents the transformation of one element into another during radioactive decay, ensuring that the total number of protons and neutrons is conserved. Each side of the equation must have the same mass number and atomic number. This is crucial for accurately depicting the decay pathways of isotopes like 100Tc to 100Mo.
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Decay Pathways

Decay pathways refer to the different routes through which a radioactive isotope can decay into a stable or less stable isotope. For 100Tc, the two common pathways include beta decay, where a neutron is converted into a proton, and positron emission, where a proton is converted into a neutron. Each pathway results in the formation of 100Mo but involves different particles and energy changes.
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