SC15.8.18 | ALEX

Science (2015) Grade(s): 8

Developing and Using Models

Structure and Function

Students know:

A medium is not required to transmit electromagnetic waves.
A sound wave, a type of mechanical wave, needs a medium through which it is transmitted.
When a sound wave strikes an object, it is absorbed, reflected, or transmitted depending on the object's material.
When a light wave shines on an object, it is absorbed, reflected, or transmitted depending on the object's material and the frequency of the light.
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 path of light bends.
The absorption, reflection, and transmission of light and sound waves can be identified by observing relevant characteristics of the wave, such as frequency, amplitude, and wavelength.
Materials with certain properties are well-suited for particular functions (e.g., lenses and mirrors, sound absorbers in concert halls, colored light filters, sound barriers next to highways).

Students are able to:

Develop models of light and sound waves and identify the relevant components.
Describe the relationships between components of the model.
Use observations from the model to provide causal accounts for events and make predictions for events by constructing explanations.

Students understand that:

Light and sound waves differ in how they interact with different types of media.
The absorption, reflection, and transmission of light and sound waves depends on the type of media through which they are transmitted.
Materials with certain properties are well-suited for particular functions (e.g., lenses and mirrors, sound absorbers in concert halls, colored light filters, sound barriers next to highways).