Question

n/p ratio during positron decay:

• A. increases
• B. decreases
• C. remains constant
• D. All of these

Hint:

\(\beta^+\) decay: \(p \rightarrow n\) \(\Rightarrow\) \(n\) increases, \(p\) decreases \(\Rightarrow\) \(n/p\) ratio increases.

Answer 1

The Correct Option is A

To understand the changes in the n/p (neutron/proton) ratio during positron decay, let's first explore what positron decay is and how it affects the composition of an atomic nucleus.

Positron Decay: Positron decay is a type of radioactive decay in which a proton within a nucleus is transformed into a neutron, emitting a positron and a neutrino in the process. The transformation can be represented by the equation:

\(p^+ \rightarrow n + e^+ + \nu_e\)

Here:

• \(p^+\): Proton
• \(n\): Neutron
• \(e^+\): Positron
• \(\nu_e\): Neutrino

Effect on n/p Ratio: In positron decay, the number of protons decreases by one, while the number of neutrons increases by one. As a result, the neutron/proton (n/p) ratio increases. This is because after the decay:

• The total number of neutrons increases, leading to a higher numerator in the n/p ratio.
• The total number of protons decreases, leading to a smaller denominator in the n/p ratio.

Conclusion: The n/p ratio increases during positron decay as a consequence of a proton converting into a neutron. Therefore, the correct answer is:

Increases

Let's re-evaluate the options:

• Increases: Correct, as explained above.
• Decreases: Incorrect, as the n/p ratio does not decrease in this process.
• Remains constant: Incorrect, because both neutrons and protons undergo changes.
• All of these: Incorrect, as only one effect (increase) is true for this decay type.