2. Exploring the application of colloid (Reflection )

This video was a great introduction to colloids, a type of mixture that is in between a solution and a suspension. I learned that colloids are heterogeneous mixtures, meaning they are made up of two or more phases that are distinct from each other. However, unlike suspensions, the particles in a colloid are much smaller and are not visible to the naked eye. Instead, they are just large enough to scatter light, which is why colloids appear cloudy or opaque. 

Here's a summary of my key takeaways from the video:

• Colloids are everywhere: From the milk in your coffee to the fog outside your window, colloids are all around us. They're mixtures where one substance is dispersed throughout another, but the particles are too small to settle out like in a suspension, and not small enough to dissolve completely like in a solution.

• There are different types of colloids: The video talks about emulsions (like mayonnaise), foams (like whipped cream), and gels (like Jello). Each type has its own unique properties and applications.

• Colloids are stabilized by science: Tiny particles in colloids have a tendency to clump together, but things like emulsifiers and electrical charges can help keep them dispersed. The video explains some of the science behind this, like the Tyndall effect, which is why colloids often appear cloudy or opaque.

• Colloids are important in many industries: From food and cosmetics to medicine and materials science, colloids play a vital role in many different products and processes.

One of the most interesting things I learned about colloids is that they are all around us in our daily lives. Milk, mayonnaise, fog, and smoke are all examples of colloids. I was also surprised to learn that some colloids, like gelatin and starch, can spontaneously form when mixed with water. This means that there are colloids out there that we may not even be aware of!

Learning about colloids has made me more conscious of the different types of mixtures that exist in the world around me. I am now more likely to pay attention to the things that I see and wonder whether they are solutions, suspensions, or colloids. I think it is important to be aware of the different types of mixtures because they have different properties and can be used for different purposes. For example, colloids are used in many different industries, such as food, cosmetics, and medicine.

Overall, I found this video to be very informative and engaging. Professor Dave Explains does a great job of breaking down complex topics into easy-to-understand concepts. I would definitely recommend this video to anyone who is interested in learning more about colloids.

Based on the examples in the video, here's the making of condensed milk which is an example of colloid. 

Condensed milk is an example of a colloid, specifically an emulsion. It is made by heating milk, butter and sugar together until much of the water content has evaporated, resulting in a thick, syrupy liquid that contains small droplets of milk proteins and fat dispersed in a sugar solution. These small droplets give condensed milk its characteristic creamy texture and opaque appearance, making it a colloid.