 Have to go through a medium (air, water, rock)  The disturbance travels not the particles.

 Does not have to pass through a medium  Particles move up and down

 Crest- the highest point  Trough- the lowest point Rest position - the position of the wave before any disturbance

 the greatest distance that wave particles move from their rest position

Fig. 7.2

 the distance between one point in the wave to the nearest point just like it Transverse: › Crest to crest › Trough to trough Longitudinal: - Compression to Compression - Rarefaction to Rarefaction wavelength

–shorter wavelength  higher frequency  1 second

 Humans can hear 20Hz to 20KHz  Lose hearing of high pitches as you get older  Bass lower frequency and less energy

1. Indicate the interval which represents one full wavelength. A. a to c B. b to d C. a to g D. c to g

Type of RadiationWavelengthDangerousDetected ByBlocked By RadioLongestNoRadio Receiver Viaducts, Power lines MicrowavesLongerNoHeated FoodWater Infrared (heat)LongNoThermometerClouds Light (ROY G BIV) MediumNoEyes Ultra VioletShortYesSkinOzone Layer X-RaysShorterYesFilmEarth’s Magnetic Field GammaShortestYesGeiger Counter Earth’s Magnetic Field

Three Series of Spectral Lines of Atomic Hydrogen Fig. 7.9

Emission and Absorption Spectra of Sodium Atoms Fig. 7.B