Radiation is the emission and transfer of energy through space or a material medium in the form of waves or particles.

Types of Radiation:

1. Electromagnetic Radiation:Energy travels in the form of electromagnetic waves (no need for a medium).Examples:

   • Light

   • Radio waves

   • Microwaves

   • Infrared

   • Ultraviolet

   • X-rays

   • Gamma rays

2. Particle Radiation:Energy is carried by moving particles, usually from radioactive materials.Examples:

   • Alpha particles

   • Beta particles

   • Neutrons

3. Acoustic Radiation:Transfer of energy through mechanical waves in a medium (like sound in air or water).

4. Thermal Radiation:Emitted by all objects with temperature above absolute zero, mainly in the infrared spectrum.

Key Point:

Radiation can be ionizing (high-energy, can damage cells—like X-rays, gamma rays) or non-ionizing (low-energy, generally safe—like visible light, radio waves).