Y7S2U3 Lesson 3 Separating Insoluble Substances

Summary

This lesson covers techniques for separating insoluble substances, focusing on physical properties like magnetism, size, and density. Students will learn about five separation methods: centrifuging (spinning to separate based on density), decanting (pouring to separate sediment from liquid), sieving (separating larger particles based on size), filtration (using filters for smaller particles), and magnetic separation (using magnets to extract metals). These methods are crucial for understanding how to separate waste from oceans and other practical applications. The lesson emphasizes the importance of physical properties in determining the best separation technique.

Takeaways

• 🔍 Insoluble substances do not dissolve and form heterogeneous mixtures.
• 🌊 Oceans are filled with waste materials like plastic, wood, metals, and more, many of which are insoluble.
• 🧲 Physical properties such as magnetism, size, and density help separate insoluble substances.
• 🏗️ Five separation techniques for insoluble substances include centrifuging, decanting, sieving, filtration, and magnetic separation.
• ⚙️ Centrifuging separates substances based on density by spinning mixtures rapidly, such as in washing machines and blood tests.
• 🍝 Decanting involves carefully pouring liquid away from sediment, like pouring water off pasta or separating oil from water.
• 🔠 Sieving uses size differences to separate larger particles from mixtures, such as in gold panning or construction sites.
• 💧 Filtration, similar to sieving, separates smaller particles that can pass through a sieve but not through filter paper.
• 🧲 Magnetic separation uses magnetism to separate metals like iron, nickel, and cobalt from non-magnetic materials.
• 📋 The physical properties used to separate substances include density, size, and magnetism, and students will practice these techniques.

Q & A

What is an insoluble substance?

An insoluble substance is a material that does not dissolve in a liquid, leading to the formation of heterogeneous mixtures.

Why are heterogeneous mixtures important in the context of ocean waste?

Many types of waste found in the ocean, such as plastic, wood, metals, and glass, are insoluble in water, forming heterogeneous mixtures that can be separated using various physical properties.

What are the five physical properties mentioned that help separate insoluble substances?

The five physical properties are magnetism, size, density, melting point, and boiling point.

What physical properties are focused on in this lesson?

The lesson focuses on magnetism, size, and density.

How does density help in separating mixtures?

Density determines how closely packed particles are. Substances with low density float, while those with high density sink, aiding in their separation.

What role does size play in separating insoluble substances?

Size helps separate larger substances from smaller ones. Techniques like sieving and filtration use size to separate materials based on their dimensions.

What is magnetism and how does it aid in separating substances?

Magnetism refers to a material's ability to be attracted by a magnet. Magnetic substances like iron, nickel, cobalt, and steel can be separated from non-magnetic substances using this property.

What is centrifuging, and how does it separate substances?

Centrifuging is the rapid spinning of a mixture to separate light from heavy substances. This technique uses the property of density to separate components.

How does decanting work to separate mixtures?

Decanting involves carefully pouring a liquid off a denser solid, like sediment, which stays at the bottom. It uses the property of density.

What is the difference between sieving and filtration?

Both techniques separate substances by size, but sieving removes larger particles, while filtration separates smaller particles that may pass through a sieve but not through filter paper.