The Nature of Light: Gave important information about the structure of the atom Light behaves like waves rippling from a rock thrown in the water Einstein VERSUS

How can most light be created from lightbulbslightbulbs with the minimum (lowest amount) of energy. Electromagnetic energy could be emitted only in quantized formquantized Quanta or Photons: Discrete (specific) amounts of bundles of energy that light is made of.

Modern Theory Views of Light Dual Nature: particle and wave

Basic Properties of Light as Waves  Wavelength(λ) : the distance between two neighboring peaks or troughs  Frequency: the number of peaks that pass a given point each second (Hertz) Velocity: the distance a peak move in a unit of time

Electromagnetic Radiation Electromagnetic radiation  Is energy that travels as waves through space.  Is described in terms of wavelength and frequency.  Moves at the speed of light in a vacuum. speed of light = 3.0 x 10 8 m/s

What is the Electromagnetic Spectrum? Full range of frequencies,from radio to gamma waves, that characterizes light. Electromagnetic waves is another way of saying light. Some we can see. Some we can not.

AstroCappella: High Energy Groove Music by Padi Boyd and Jim Heagy Lyrics by Alan Smale and Padi Boyd Chorus:X Rays, Gamma Rays, high energyHot stars, heavy stars, high densityQuasars, black holes, supernovaePowerhouses lighting up the GalaxyFlashing, bursting, pulsing objects we could seeIf we had X-ray eyes, if we had X-ray eyesX RaysGamma Rays density Going up the spectrum, repeat after meRadio, infrared, visible, UVinfraredUV Keep going all the way what do you see?That's X-rays, gamma rays, high energyAn X-ray photon has a high frequency Which means a shorter wavelength than you could ever see Song

Electromagnetic Spectrum The electromagnetic spectrum  Arranges forms of energy from lower to higher.  Arranges energy from longer to shorter wavelengths.  Shows visible light with wavelengths from nm. Copyright © 2007 by Pearson Education, Inc. Publishing as Benjamin Cummings

Spectra White light that passes through a prism  is separated into all colors called a continuous spectrum.  Gives the colors of a rainbow. Copyright © 2007 by Pearson Education, Inc. Publishing as Benjamin Cummings

Atomic Spectrum An atomic spectrum consists of  Lines of different colors formed when light from a heated element passes through a prism.  Photons emitted when electrons drop to lower energy levels. spectrum Copyright © 2007 by Pearson Education, Inc. Publishing as Benjamin Cummings

Solution 1. Which of the following has the shortest wavelength? C. UV light 2. Which of the following has the lowest energy? A. red light

Learning Check 1. Which of the following has the shortest wavelength? A. microwaves B. blue light C. UV light 2. Which of the following has the lowest energy? A. red light B. blue light C. green light