Absorption and Transmission of Light

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What do we really mean when we say “the object is red because it reflects red and absorbs all other colors”? Even high school students who can recite this fact have a hard time grasping the implications of that fact. The confusion lies in their lack of a concrete experience with the phenomena – it may be common knowledge that “white” light is made of of many colors and wavelengths, but until they are separated out and studied, the STEM concepts remain abstract and difficult to grasp.

Gummy Bears and lasers come together in this fascinating question, “What happens when you shine green light on a red gummy bear, or red light on a green gummy bear”? In addition to making color theory a bit more clear, this is a great exploration of the otherwise abstract concepts that describe the most basic of light-matter interactions: Absorption, transmittance and reflection of light.

 

Grade Range:
7 to 12

Duration
1/2 Hour – 1 Hour

Supplies

Red and Green and Clear Gummy Bears, a Red Laser and a Green Laser, a White LED, and some plain white paper

NGSS Connections

PS4.B: Electromagnetic Radiation

  • Develop and use a model to describe that waves are reflected, absorbed, or transmitted through various materials (MS-PS4-2)
  • When light shines on an object, it is reflected, absorbed, or transmitted through the object, depending on the objects’s material and the frequency of light. (MS-PS4-2)
  • Evaluate the validity and reliability of claims in published materials of the effects that different frequencies of electromagnetic radiation have when absorbed by matter. (HS-PS4)