Nuclear Radiation and Radioactivity

Nuclear Radiation

• Definition: High-energy particles or rays emitted from the nucleus of an atom
• Types:
  • Ionizing radiation: capable of removing tightly bound electrons from atoms, resulting in ions
  • Non-ionizing radiation: does not have enough energy to remove electrons from atoms

Radioactivity

• Definition: Spontaneous emission of ionizing radiation by unstable atomic nuclei
• Causes:
  • Unstable atomic nuclei
  • Radioactive decay: process by which unstable nuclei become stable
• Types of radioactive decay:
  • Alpha decay
  • Beta decay
  • Gamma decay

Half-Life

• Definition: Time required for half of the radioactive atoms in a sample to decay
• Formula: t½ = ln(2) / λ (where λ is the decay constant)
• Characteristics:
  • Constant for a given radioactive substance
  • Independent of the initial amount of substance

Alpha (α) Rays

• Definition: High-energy helium nuclei (2 protons, 2 neutrons) emitted from the nucleus of an atom
• Properties:
  • High ionizing power
  • Short range (stopped by paper or human skin)
  • High biological effectiveness

Beta (β) Rays

• Definition: High-energy electrons emitted from the nucleus of an atom
• Properties:
  • Lower ionizing power than alpha rays
  • Longer range than alpha rays (stopped by wood or metal)
  • Lower biological effectiveness than alpha rays

Gamma (γ) Rays

• Definition: High-energy electromagnetic radiation emitted from the nucleus of an atom
• Properties:
  • No mass or charge
  • Highest energy and penetrating power among the three
  • Can travel long distances in air and through solid objects
  • Low biological effectiveness due to low ionizing power

This quiz covers the basics of nuclear radiation, including types of radiation, radioactivity, half-life, and properties of alpha, beta, and gamma rays.