Radioactive Decay
Types of Radioactive Decay
- Alpha decay: the loss of an α-particle
- α-particle: a helium nucleus
- Beta decay: the loss of a β-particle
- β-particle: a high-energy electron
- Positron emission: the loss of a positron
- Positron: a particle that has the same mass as, but an opposite charge to, that of an electron
- Gamma emission: the loss of a γ-ray
- γ-ray: high-energy radiation that almost always accompanies the loss of a nuclear particle:
- Electron capture (K-capture): addition of an electron to a proton in the nucleus
- The result of this process is that a proton is transformed into a neutron
Kinetics of Radioactive Decay
- Nuclear transmutation is a first-order process.
- The kinetics of such a process obey this equation:
- ln(Nt/N0) = −kt
- Nt is the mass, or number of particles at time t.
- No is the original.
- The half-life of such a process is
- 0.693/k=t1/2
- Comparing the amount of a radioactive nuclide present at a given point in time with the amount normally present, one can find the age of an object.