 # Waves. Characteristics of Waves Frequency Amplitude.

## Presentation on theme: "Waves. Characteristics of Waves Frequency Amplitude."— Presentation transcript:

Waves

Characteristics of Waves

Frequency

Amplitude

Wavelength

Calculating wavelength and frequency  C = λv  C = speed of light 3x10 8 m/s  Λ = wavelength in meters  v = frequency in Hz  What is the wavelength of a microwave having a frequency of 3.44x10 9 Hz?

Practice  Do one on your own  Complete worksheet for homework

Electromagnetic Wave

EM Spectrum

Visible Light

Refraction  Mediums refract light according to specific wavelength

Particle Nature of light

Quanta  Max Planck  Matter can gain or lose energy in small, specific amounts called QUANTA  E quantum = hv  E = energy  h = Planck’s constant 6.626x10 -34 JS  V = frequency

What does this mean  Energy is absorbed or released in discrete whole quanta 1hv, 2hv, 3hv 1hv, 2hv, 3hv  Cool but the wave model could not not explain the photoelectric effect

Photoelectric effect  Shine light at a metal and try to eject electrons

Photoelectric effect  No matter how long you shine lower energy light (lower frequency), electrons are not ejected  But even a dim light of a certain higher frequency does eject the electrons

E quantum = hv  E is energy (Joules)  h = Planck’s constant 6.626x10-34Js  v = frequency

Einstein  Proposed that light acts like a wave AND a particle.  Think of it as a stream of tiny particles  These particles are called photons  PHOTON = particle of electromagnetic radiation with no mass that carries a quantum of energy

Atomic Emission spectrum  Each element has a unique spectral signature