CK-12-Physics - Intermediate

(Marvins-Underground-K-12) #1

http://www.ck12.org Chapter 23. Quantum Physics


23.1 Blackbody Radiation and Planck’s Quan-


tum Hypothesis


Objectives


The student will:



  • Understand how difficulty with blackbody radiation leads to the particle interpretation of light.

  • Understand Planck’s quantum hypothesis.


Vocabulary



  • blackbody radiation:Ideal approximation of the different spectra of different substances.

  • Planck’s constant:h= 6. 626 × 10 −^34 J−s,used in Planck’s equation.

  • quantized:Not-continuous, discrete.


Blackbody radiation


FIGURE 23.2


Glowing iron displays a range of colors
between red, orange, and yellow

As objects heat up, they generally begin to glow, giving off light like the hot iron in the picture above. As their
temperature goes up, more light and a different spectrum of light results. Different substances have different spectra,
but many approximate an ideal known asblackbody radiation.

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