Beta-minus decay is a type of radioactive decay in which a neutron inside an unstable nucleus transforms into a proton, emitting an electron (beta particle) and an antineutrino in the process.
Key Features:
- The atomic number increases by one, as a new proton is formed.
- The mass number remains unchanged, since the total number of nucleons (protons + neutrons) stays the same.
- This process changes the element into the next one in the periodic table.
Why It Happens:
- It occurs when a nucleus has too many neutrons compared to protons, making it unstable.
- Converting a neutron into a proton helps the nucleus move toward a more stable neutron-to-proton ratio.
Role of the Antineutrino:
- The emitted electron antineutrino carries away energy and momentum, ensuring conservation laws are satisfied.
- It interacts extremely weakly with matter, making it very difficult to detect.
Example:
A common example is the decay of carbon-14 into nitrogen-14, used in radiocarbon dating.
In essence, beta-minus decay is a fundamental process that reshapes the identity of an element by altering a neutron into a proton, while releasing an electron and an elusive antineutrino.