Transcription
Hey, so what we're going to be talking about today is the Tyndall effect.
Now, the Tyndall effect is a phenomenon where light scatters through a homogeneous mixture like a colloid or a very fine suspension, but it doesn't scatter through a homogeneous mixture like a solution. So, this happens because the larger particles in a colloid or suspension scatter and reflect light. So, the light's bouncing different ways, causing the beam to be big enough that it's actually visible to the naked eye. Think about like headlights passing through fog, right? You can see them, but only in fog where there's water particles suspended in the air.
Now, this effect doesn't happen in a solution because the particles are actually too small, they're too finely distributed. Um, and so the beam of light passes through the solution without being visible.
So, to illustrate this, I'm going to use a laser pointer. This is a laser pointer right here. And so we have four different substances. We have water, which is just a compound, H2O. We have vegetable oil, which is a solution. We have diluted milk. So, I basically just took standard almond milk and then I diluted it with enough water so you can at least see the beam, so kind of making it like fog. And then also here, I have flour, which I mixed in water, and this will be just a suspension. So I'll have to kind of shake it up a little bit too, so you can see what's going on here.
So, I'm going to take the laser pointer and let's look at water. If you look at water, you'll see that you can kind of see the reflections on the glass, but other than that, you can't see the beam passing through it.
Now, for the vegetable oil, if you look at the vegetable oil, you can just barely see that beam passing through it. So, you know, really not visible. And especially I have the lights down in here just so you can kind of see that beam. So, not really that visible.
Now, we're going to take diluted milk, which is an actual colloid, and look at that. You can see that beam absolutely clearly. It's scattering enough of the light where the beam actually becomes visible.
And so then now here you have flour and water. So, what I'm going to do is, is I'm going to kind of shake this, this up a little bit so you can see, so it mixes it. And then let me see if I can get this. Yeah, look at that. And you can actually see the particles in the actual water too. So, those are the particles of flour that you're seeing.
So, just to compare the last two, you know, this is a colloid, it's more evenly distributed, um, than a suspension, but not as evenly distributed as a solution. And then right there, you can see the actual particles. So, that is the Tyndall effect.