LIGHT REVIEW MRS. ROSE HCHEM 2015

WHAT IS THE WAVELENGTH AND FREQUENCY OF LINE 1 AND LINE 2?

ENERGY OF WAVES – IT TAKES MORE ENERGY TO TRAVEL AT A HIGHER FREQUENCY… Low frequency High frequency, short wavelength Amplitude Low frequency, long wavelength short wavelength 

What kind of relationship exists between wavelength and frequency? A)Logarithmic B)Quadratic C)Direct D)Inverse Rueben’s TubeTones

ELECTROMAGNETIC RADIATION Vision

VISIBLE PART OF EM SPECTRUM PRISM Slit Ray of White Light Waves 1 / 33,000 ” long Waves 1 / 70,000 ” long R ed O range Y ellow G reen B lue I ndigo V iolet 400 nm – 700 nm

VOCABULARY OF A WAVE Zumdahl, Zumdahl, DeCoste, World of Chemistry  2002, page 324 A c = speed of light = x 10 8 m/s (really fast, true for every kind of light!)

FREQUENCY O’Connor, Davis, MacNab, McClellan, CHEMISTRY Experiments and Principles  1982, page second Frequency 4 cycles/second = 4 hertz 12 cycles/second = 12 hertz 36 cycles/second = 36 hertz

WAVES Wavelength ( ) - length of one complete wave. Common units: m or nm Frequency () - # of waves that pass a point during a certain time period (usually per second) Common Units: hertz (Hz) = 1/s = s -1 Amplitude (A) - distance from the origin to the trough or crest (height of one wave) Courtesy Christy Johannesson

WHICH COLOR OF VISIBLE LIGHT HAS THE LONGEST WAVELENGTH? A) YELLOW B) BLUE C) RED D) VIOLET

WHICH TYPE OF LIGHT HAS MORE ENERGY THAN VISIBLE LIGHT BUT LESS ENERGY THAN GAMMA RAYS? A) Radiowaves B) Microwaves C) Infrared D) UV rays

REVIEW 1) Which color of light (Red or Violet) does wave B represent? 2) Which wave has the lowest frequency? 3) Which wave has the most energy? 4) Which wave has the shortest wavelength? 5) Which wave travels the fastest?

WHAT HAPPENS WHEN RED, GREEN AND VIOLET LIGHT ARE DIRECTED AT A GLOW-IN- THE-DARK SURFACE? FRISBEE DEMO!!

Vs.

REVIEW QuantizedContinuous

ABSORPTION AND EMISSION

absorption and emission