1. Unstable Nucleus: The atom starts with an unstable nucleus, meaning it has an imbalance in the number of protons and neutrons. This instability causes the nucleus to release energy to become more stable.
2. Emission of Particles/Energy: The unstable nucleus releases energy in the form of:
* Alpha particles: These are made of two protons and two neutrons, essentially a helium nucleus.
* Beta particles: These are high-energy electrons (or positrons, their antimatter counterpart).
* Gamma rays: These are high-energy electromagnetic radiation.
3. Nuclear Transformation: The emission of these particles changes the composition of the nucleus:
* Alpha decay: The atomic number decreases by 2, and the mass number decreases by 4. This effectively means the atom transforms into a different element.
* Beta decay: The atomic number increases by 1, but the mass number remains the same. Again, the atom transforms into a different element.
* Gamma decay: The atomic number and mass number remain the same, but the atom enters a more stable energy state.
4. Daughter Nuclide: The atom that results from radioactive decay is called the daughter nuclide. It may be stable, or it may also be radioactive and undergo further decay.
Examples:
* Uranium-238 (U-238) undergoes alpha decay, transforming into Thorium-234 (Th-234).
* Carbon-14 (C-14) undergoes beta decay, transforming into Nitrogen-14 (N-14).
In summary, radioactive decay is a fundamental process that alters the atomic structure of an atom, creating a new element or a more stable state. This process is crucial in understanding the natural world and has numerous applications in medicine, energy production, and scientific research.
