Wave Properties

A wave is a disturbance that transfers energy, not matter. Its key properties are its wavelength (λ, the length of one wave), frequency (f, how many waves pass per second), and amplitude (height/intensity).

Formula: v = fλ

Wave-Particle Duality of Light

Light is strange. It travels through space like a wave, but it interacts with matter in discrete packets of energy called photons. Light is both a wave and a particle.

Photon Energy

The energy of a single photon is directly proportional to its frequency. Higher frequency light (like violet) has higher energy photons than lower frequency light (like red).

Formula: E = hf

The Electromagnetic Spectrum

Radio waves, microwaves, visible light, and X-rays are all the same type of wave (electromagnetic radiation), just with different frequencies and wavelengths.

Ionizing vs. Non-Ionizing Radiation

This is the most important safety distinction. High-frequency radiation (UV, X-rays, Gamma rays) is ionizing, meaning its photons have enough energy to knock electrons out of atoms and damage DNA. Low-frequency radiation (radio, microwaves, visible light) is non-ionizing and does not do this.