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Everything Science www.everythingscience.co.za
12. Optical phenomena and properties of matter
Physics
Grade 12
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Everything Science www.everythingscience.co.za
Photoelectric effect
The photoelectric effect is the process whereby an e...
3
Everything Science www.everythingscience.co.za
Work function
A substance has a work function which is the minimum energy...
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Everything Science www.everythingscience.co.za
Emission and absorption spectra
Emission spectra are formed when certain ...
5
Everything Science www.everythingscience.co.za
For more practice see: everythingscience.co.za
Shortcode: ESCQW
5
Everything Science www.everythingscience.co.za
For more practice see: everythingscience.co.za
Shortcode: ESCQW
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Optical phenomena and properties of matter

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Grade 12 summary presentation for optical phenomena and properties of matter

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Optical phenomena and properties of matter

  1. 1. 1 Everything Science www.everythingscience.co.za 12. Optical phenomena and properties of matter Physics Grade 12
  2. 2. 2 Everything Science www.everythingscience.co.za Photoelectric effect The photoelectric effect is the process whereby an electron is emitted by a substance when light shines on it. The number of electrons ejected increases with the intensity of the incident light. The photoelectric effect illustrates the particle nature of light and establishes the quantum theory.
  3. 3. 3 Everything Science www.everythingscience.co.za Work function A substance has a work function which is the minimum energy needed to emit an electron from the metal. The frequency of light whose photons correspond exactly to the work function is known as the cut-off frequency. EK , max=hf−W0 W0=hf0
  4. 4. 4 Everything Science www.everythingscience.co.za Emission and absorption spectra Emission spectra are formed when certain frquencies of light are emitted by a gas, as a result of electrons in the atmoms dropping from higher to lower energy levels. The pattern of the spectra is charactersistic of the specific gas. Absorption spectra are formed when certain frequencies of light are absorbed by a material. These photons are absorbed when their energy is exactly the correct amount to raise an electron from one energy level to another.
  5. 5. 5 Everything Science www.everythingscience.co.za For more practice see: everythingscience.co.za Shortcode: ESCQW
  6. 6. 5 Everything Science www.everythingscience.co.za For more practice see: everythingscience.co.za Shortcode: ESCQW

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