Radiation

Alpha Radiation (α):
- Composed of 2 protons and 2 neutrons (a helium nucleus).
- Charge: +2
- Mass: Large (compared to beta or gamma).
- Penetration: Low; stopped by a sheet of paper or skin.
- Ionizing Power: High.
Beta Radiation (β):
- Composed of high-energy electrons (β⁻) or positrons (β⁺).
- Charge: -1 (β⁻) or +1 (β⁺).
- Mass: Small (much lighter than alpha particles).
- Penetration: Medium; stopped by a few mm of aluminium.
- Ionizing Power: Medium.
Gamma Radiation (γ):
- Electromagnetic waves (not particles).
- Charge: None.
- Mass: None.
- Penetration: High; stopped by thick lead or concrete.
- Ionizing Power: Low.

Radioactive Decay:
- The process by which unstable nuclei lose energy by emitting radiation.
- This can involve alpha, beta, or gamma radiation.
Half-life:
- The time it takes for half the nuclei in a radioactive sample to decay.
- Used to measure the rate of decay.
Background Radiation:
- Radiation that is always present in the environment.
- Sources include:
  - Natural: Cosmic rays, radon gas, rocks.
  - Artificial: Medical procedures (e.g., X-rays), nuclear power.
Uses of Radiation:
- Medical: Radiotherapy, sterilizing medical equipment, and imaging.
- Industrial: Smoke detectors (alpha), thickness monitoring (beta).
- Scientific: Carbon dating, radioactive tracers.
Dangers of Radiation:
- Ionizing Radiation: Can damage or mutate DNA, leading to cancer.
- Precautions: Use shielding (e.g., lead), minimize exposure time, and maintain distance from sources.

Activity (A):
A=N/t
where A is activity in becquerels (Bq), N is the number of decays, and t is time.
Nuclear Equations:
- Alpha decay: Parent Nucleus→Daughter Nucleus+α\text{Parent Nucleus} \rightarrow \text{Daughter Nucleus} + \alphaParent Nucleus→Daughter Nucleus+α
- Beta decay: Parent Nucleus→Daughter Nucleus+β\text{Parent Nucleus} \rightarrow \text{Daughter Nucleus} + \betaParent Nucleus→Daughter Nucleus+β