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Beta Decay is a type of radioactive disintegration involving the emission of an electron or a positron accompanied by an uncharged antineutrino or neutrino. Here’s a detailed look at beta decay:
Characteristics of Beta Decay:
- Process:
- Emission of Electron (β⁻ Decay): A neutron in the nucleus transforms into a proton, an electron (beta particle), and an antineutrino. The atomic number increases by one, but the mass number remains unchanged.
- Emission of Positron (β⁺ Decay): A proton in the nucleus transforms into a neutron, a positron, and a neutrino. The atomic number decreases by one, but the mass number remains unchanged.
- Particles Involved:
- Electron (β⁻): A negatively charged particle.
- Positron (β⁺): A positively charged particle, which is the antiparticle of the electron.
- Neutrino (ν): A nearly massless, neutral particle.
- Antineutrino (ν̅): The antiparticle of the neutrino, also nearly massless and neutral.
- Changes in Nucleus:
- β⁻ Decay: Increases the atomic number by one.
- β⁺ Decay: Decreases the atomic number by one.
- The mass number remains the same in both types of beta decay.
Examples of Beta Decay:
- β⁻ Decay:
- Carbon-14 to Nitrogen-14:
\( ^{14}_6C \rightarrow ^{14}_7N + e^- + \overline{\nu}_e \) - A neutron in carbon-14 transforms into a proton, emitting an electron and an antineutrino, resulting in nitrogen-14.
- β⁺ Decay:
- Potassium-40 to Argon-40:
\( ^{40}{19}K \rightarrow ^{40}{18}Ar + e^+ + \nu_e \) - A proton in potassium-40 transforms into a neutron, emitting a positron and a neutrino, resulting in argon-40.
Importance of Beta Decay:
- Nuclear Stability:
- Beta decay helps unstable nuclei transform into more stable configurations.
- Radioactive Dating:
- Used in techniques like radiocarbon dating to determine the age of archaeological samples.
- Medical Applications:
- Used in medical imaging and treatments, such as positron emission tomography (PET scans).
- Particle Physics:
- Provides insights into the weak nuclear force, one of the four fundamental forces in nature.
Summary:
Beta decay is a process of radioactive disintegration that involves the emission of an electron or positron along with a neutrino or antineutrino. It results in a change in the atomic number of the nucleus while the mass number remains unchanged. Beta decay plays a crucial role in nuclear stability, radioactive dating, medical applications, and particle physics.
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