MS - PS4.B (A) - Properties of Visible Light (ASSIGNED - RC 3/3/2014)

Module: Properties of Electromagnetic Radiation

DCI: PS4.B (A)When light shines on an object, it is reflected, absorbed, or transmitted through the object, depending on the object’s material and the frequency (color) of the light.

DCI: PS4B (B) The path that light travels can be traced as straight lines, except at surfaces between different transparent materials (e.g., air and water, air and glass) where the light path bends.

PE: MS-PS4-2 Develop and use a model to describe that waves are reflected, absorbed, or transmitted through various materials.

[Clarification Statement: Emphasis is on both light and mechanical waves. Examples of models could include drawings, simulations, and written descriptions.] [Assessment Boundary: Assessment is limited to qualitative applications pertaining to light and mechanical waves.]

The ideas in this standard are: 

- when light shines on an object, it is reflected, absorbed, or transmitted through the object

- what happens to light when it strikes an object depends on the objects material and the frequency of the light

- light travels in straight lines, except when it moves from one transparent material to another (and it bends)

There is plenty of content to write about, although we should avoid low-level vocabulary questions (which might be very tempting).  We can, though, provide scenarios and ask what is happening to the light.  One other word of caution: avoid situations where we limit ourselves to three reasonable answers (reflected, absorbed, transmitted), we can do this by providing descriptions of the light interaction rather than restricting ourselves to a certain one word answer.  

Students can 'model' light interactions by choosing from diagrams, written descriptions, or perhaps even differentiating between types of evidence. 

Possible Question Starters: 

"A student places a pencil in a glass of water and observed that the pencil appeared broken.

Which of these provides the best explanation for why the pencil appears broken?"

correct answer - the light bends as it travels from the air into the water

incorrect answer - the water reflects light away from the pencil 

"The diagram shows four possible behaviors of light as a lightbulb shines on a bowl of water.  Which of the four possibilities shows reflection?"

Correct answer - Z

Of these two questions, we prefer the first one.
The second one only asks for a label to be applied. This is what the TEKS want, but NGSS wants more.

Perhaps we could have some design challenges?
Light beam and target in an image. We ask what can be put at point X to get the beam to the target.

Maybe questions like we had for the sound assessment.