Answered

Use the equation to answer the question.

${ }_6^{14} C \rightarrow{ }_7^{14} N+{ }_{-1}^0 e$



Which type of radioactive decay does the equation model?


Abeta-plus decay
Bgamma decay
Calpha decay
Dbeta-minus decay

Verified Answer :

  • Analyze the provided nuclear equation \({}_{6}^{14} \text{C} \rightarrow {}_{7}^{14} \text{N} + {}_{-1}^{0} e\), noting the change from atomic number 6 to 7 and the emission of an electron.
  • Compare these characteristics against standard radioactive decay types: alpha, gamma, beta-plus, and beta-minus.
  • Observe that the increase in atomic number and the emission of an electron are the defining features of beta-minus decay.
  • Conclude that the equation models \(\boxed{\text{beta-minus decay}}\).

Explanation

  1. Analyzing the Nuclear Equation

The given nuclear equation is \({}_{6}^{14} \text{C} \rightarrow {}_{7}^{14} \text{N} + {}_{-1}^{0} e\).
To identify the type of decay, we examine the changes in the atomic number and the mass number of the nucleus, as well as the identity of the emitted particle.

  1. The initial nucleus is Carbon-14 (\({}_{6}^{14} \text{C}\)), which has an atomic number \(Z = 6\) and a mass number \(A = 14\).
  2. The final nucleus is Nitrogen-14 (\({}_{7}^{14} \text{N}\)), which has an atomic number \(Z = 7\) and a mass number \(A = 14\).
  3. The emitted particle is \({}_{-1}^{0} e\), which represents an electron (a beta-minus particle).
  1. Identifying the Decay Type

We compare the given reaction with the characteristics of different types of radioactive decay:

  • Alpha decay: The nucleus emits an alpha particle (\({}_{2}^{4} \text{He}\)). The atomic number decreases by 2 and the mass number decreases by 4.
  • Gamma decay: The nucleus emits a high-energy photon (\({}_{0}^{0} \gamma\)). Neither the atomic number nor the mass number changes.
  • Beta-minus decay (\(\beta^-\)): A neutron in the nucleus converts into a proton and an electron. The electron (\({}_{-1}^{0} e\)) is emitted. As a result, the atomic number increases by 1, while the mass number remains unchanged.
  • Beta-plus decay (\(\beta^+\)): A proton in the nucleus converts into a neutron and a positron. The positron (\({}_{+1}^{0} e\)) is emitted. As a result, the atomic number decreases by 1, while the mass number remains unchanged.

In our equation, the atomic number increases from 6 to 7, and an electron (\({}_{-1}^{0} e\)) is emitted. This matches the description of beta-minus decay perfectly.

  1. Conclusion

Based on the analysis, the reaction \({}_{6}^{14} \text{C} \rightarrow {}_{7}^{14} \text{N} + {}_{-1}^{0} e\) represents the transformation of a neutron into a proton within the Carbon-14 nucleus, accompanied by the emission of an electron. This is the definition of beta-minus decay. Thus, the equation models beta-minus decay. The final answer is \(\boxed{\text{beta-minus decay}}\).

Examples

Radioactive decay is not just a theoretical concept; it has practical applications in fields like archaeology. Carbon-14 dating relies on the beta-minus decay of Carbon-14 isotopes found in organic materials. By measuring the ratio of the remaining Carbon-14 to the stable Nitrogen-14, scientists can determine the age of ancient artifacts, such as fossils or wooden structures, providing a window into the past. Understanding these decay processes helps us date objects that are thousands of years old with remarkable precision.