Where are we going with this? The point of this deck is to give the background information and examples so that we can differentiate between substances (pure and mixtures) based on physical and chemical properties.
What Is "Scattering Light"?
Scattering light is one of the things that classifies different types of liquid mixtures. Specifically…
Pure Substance Solution Colloid Suspension Scatter Light No No Yes Yes
So, what does it mean to scatter light? For general purposes, you can think of it this way: can you make out the details of an object through the liquid? Changing the color of the light does not matter. Something that does not scatter light allows the light to pass through.
Water does not scatter light. You can see through it. Water is a pure substance.
Water is a compound, a pure substance. It does not scatter light, as seen above.
The image of the penny is clear through the liquid.
Tea does not scatter light (unless you have messed up your tea and it's "cloudy). Tea is a solution.
|Tea is a solution, so the light does not scatter.|
|The light is tinted by the color of the solution, but it still passes through undiffused.|
Dish soap is also a solution, so it does not scatter light.
|Likewise, dish soap, despite being very thick, does not scatter light.|
|The light does not diffuse and block out the visibility of things or beams of light |
that pass through.
Milk scatters light… you can see the light coming through, but not directly. It is diffused by the large particles that are part of the mixture (colloid).
|The coffee creamer (a colloid) above and below DO scatter light. The penny cannot be seen.|
|Shining a light though the colloid results in being able to detect the light, but |
it is obviously scattered and diffused.
Muddy water scatters light. The big particles of the suspension do not let the light pass through without diffusing them.
|The muddy water suspension prevents the penny from being visible. |
|Light shined through the suspension is clearly scattered and diffused.|