Mr. Kirkman Demonstrates the Tyndall Effect

Summary

The video script explores the Tyndall effect, a phenomenon where light scatters through colloids and suspensions but not through true solutions. It demonstrates this using a laser pointer with four substances: water, vegetable oil (a solution), diluted milk (a colloid), and a flour-water suspension. The Tyndall effect is visible in the milk and suspension due to larger particles scattering light, making the light beam visible to the naked eye, akin to headlights in fog, while it's absent in the oil and water due to smaller, evenly distributed particles.

Takeaways

• 🔬 The Tyndall Effect is a phenomenon where light scatters through a colloid or fine suspension but not through a true solution.
• 🌟 The effect occurs due to the presence of larger particles in colloids or suspensions that scatter and reflect light, making the light beam visible to the naked eye.
• 🌫️ An analogy to the Tyndall Effect is the visibility of headlights in fog, where water particles suspended in the air scatter light.
• 👀 In a solution, particles are too small and finely distributed, allowing light to pass through without scattering, making the beam invisible.
• 🛠️ A laser pointer is used in the demonstration to illustrate the Tyndall Effect with different substances.
• 💧 Water (H2O) is shown as a compound that does not exhibit the Tyndall Effect due to the absence of scattering particles.
• 🥬 Vegetable oil, being a solution, barely shows the laser beam passing through, indicating no significant scattering of light.
• 🥛 Diluted milk, a colloid, clearly shows the laser beam scattering light, making the beam visible and demonstrating the Tyndall Effect.
• 🌾 Flour mixed with water forms a suspension, and when shaken, the particles scatter light, making the laser beam and particles visible.
• 🔍 The Tyndall Effect helps differentiate between colloids, suspensions, and solutions based on the visibility of light scattering.
• 📚 Understanding the Tyndall Effect is crucial for distinguishing the physical properties of different types of mixtures.

Q & A

What is the Tyndall effect?

The Tyndall effect is a phenomenon where light scatters through a colloid or a fine suspension, making the light beam visible to the naked eye, but does not scatter through a homogeneous solution where particles are too small and finely distributed.

Why does the Tyndall effect occur in colloids and not in solutions?

The Tyndall effect occurs in colloids because the larger particles in the colloid scatter and reflect light, causing the light beam to scatter in various directions and become visible. In solutions, the particles are too small to scatter light effectively, so the beam remains invisible.

What is the role of a laser pointer in demonstrating the Tyndall effect?

A laser pointer is used to illustrate the Tyndall effect by shining a beam of light through different substances. The visibility of the light beam as it passes through each substance indicates the presence of the Tyndall effect in colloids and suspensions but not in solutions.

What are the four substances used in the demonstration?

The four substances used in the demonstration are water (a compound), vegetable oil (a solution), diluted milk (a colloid), and a flour-water mixture (a suspension).

Why is the diluted milk considered a colloid?

Diluted milk is considered a colloid because it contains larger particles that are evenly distributed throughout the mixture, which allows light to scatter and become visible, characteristic of the Tyndall effect.

How does the flour-water mixture differ from the diluted milk in terms of particle distribution?

The flour-water mixture is a suspension with larger, less evenly distributed particles compared to the diluted milk, which is a colloid with more evenly distributed particles.

What can be observed when the laser pointer is shone through water?

When the laser pointer is shone through water, the light beam is not visible as it passes through, but reflections on the glass can be seen.

How visible is the light beam when it passes through vegetable oil?

The light beam passing through vegetable oil is barely visible, indicating that it does not exhibit the Tyndall effect as strongly as a colloid or suspension would.

What happens when the flour-water mixture is shaken before the laser pointer is shone through it?

Shaking the flour-water mixture ensures that the flour particles are well suspended in the water, allowing the light beam to scatter more effectively and become visible when the laser pointer is shone through it.

How does the visibility of the light beam in the diluted milk compare to the flour-water suspension?

The light beam is clearly visible in both the diluted milk (a colloid) and the flour-water suspension, but the particles in the flour-water suspension are larger and less evenly distributed, making the Tyndall effect more pronounced.

What is the significance of the Tyndall effect in understanding the properties of colloids and suspensions?

The Tyndall effect is significant because it helps distinguish between colloids and suspensions, which have larger particles that scatter light, and solutions, where particles are too small to scatter light effectively, providing insight into the physical properties of these substances.

Outlines

00:00

🌌 The Tyndall Effect: Light Scattering in Mixtures

This paragraph introduces the Tyndall effect, a phenomenon where light scatters through a colloid or fine suspension but not through a homogeneous solution. The Tyndall effect occurs due to the larger particles in colloids or suspensions that reflect and scatter light, making the light beam visible to the naked eye. The script uses the analogy of headlights in fog to explain the visibility of scattered light. To demonstrate this effect, the narrator plans to use a laser pointer with four different substances: water, vegetable oil (a solution), diluted milk (a colloid), and a flour-water suspension. The goal is to show the difference in light scattering between these substances.

Keywords

💡Tyndall Effect

The Tyndall Effect is a phenomenon where light is scattered by particles in a colloid or suspension, making the path of the light beam visible to the naked eye. It is named after the scientist John Tyndall who first described it. In the video, this effect is the central theme, and the script discusses how it occurs in colloids and suspensions but not in true solutions.

💡Colloid

A colloid is a homogeneous mixture where larger particles are dispersed throughout a fluid, but they are too small to be seen with the naked eye. In the script, diluted milk is used as an example of a colloid, demonstrating the Tyndall Effect by scattering light from a laser pointer, making the light beam visible.

💡Suspension

A suspension is a heterogeneous mixture where particles are dispersed in a fluid but are large enough to eventually settle out. The script uses a mixture of flour and water as an example, which, when shaken, shows the Tyndall Effect as the particles scatter light, revealing the light path.

💡Solution

A solution is a homogeneous mixture where the solute is completely dissolved in the solvent, and the particles are too small to scatter light. The video script mentions vegetable oil as a solution, which does not exhibit the Tyndall Effect because the particles are too fine to scatter light visibly.

💡Laser Pointer

A laser pointer is a device that emits a narrow, intense beam of light. In the video, it is used to demonstrate the Tyndall Effect by shining it through different substances to show how light is scattered or not, depending on the nature of the substance.

💡Homogeneous Mixture

A homogeneous mixture is a uniform mixture where the components are evenly distributed throughout the mixture. The script contrasts the Tyndall Effect in homogeneous mixtures like colloids and suspensions with that in solutions, which are also homogeneous but do not scatter light due to the small size of the particles.

💡Particle Size

Particle size is a critical factor in the Tyndall Effect. The script explains that larger particles in colloids and suspensions scatter light, whereas smaller particles in solutions do not, which is why the Tyndall Effect is observed in the former but not the latter.

💡Scattering

Scattering is the process by which light bounces off particles in a medium. The script describes how scattering of light by larger particles in colloids and suspensions results in the Tyndall Effect, making the light beam visible.

💡Reflection

Reflection is the bouncing back of light from a surface. The script mentions reflections on the glass when the laser pointer is shone through water, which is a different phenomenon from scattering that causes the Tyndall Effect.

💡Fog

Fog is used as an analogy in the script to explain the Tyndall Effect. Just as the light from car headlights is visible when passing through fog due to the scattering by water droplets, the Tyndall Effect is visible when light scatters through a colloid or suspension.

💡Dilution

Dilution is the process of reducing the concentration of a solute in a solution by adding more solvent. In the script, almond milk is diluted with water to create a colloid that demonstrates the Tyndall Effect by scattering light from the laser pointer.

Highlights

Introduction to the Tyndall effect.

Definition of the Tyndall effect as a light scattering phenomenon in colloids or fine suspensions.

Explanation of why the Tyndall effect does not occur in homogeneous solutions due to particle size.

Comparison of light scattering in colloids and suspensions versus solutions.

Use of a laser pointer to demonstrate the Tyndall effect.

Presentation of four substances: water, vegetable oil, diluted milk, and flour-water suspension.

Observation of light reflection in water without visible beam passage.

Minimal visibility of the laser beam in vegetable oil solution.

Clear visibility of the laser beam in diluted milk, illustrating the Tyndall effect.

Shaking the flour-water suspension to mix and demonstrate particle distribution.

Visibility of particles in the flour-water suspension, contrasting with the colloid.

Explanation of particle distribution differences between colloids and suspensions.

Visual demonstration of the Tyndall effect in the flour-water suspension.

Comparison of colloid and suspension particle visibility.

Final summary of the Tyndall effect and its observable characteristics.

Transcripts

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 poly 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 in a 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 you can just

barely see that beam passing through it

so you know really not visible and

especially i have delights 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 flower

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