Grade Level: 3rd - 5th; Type: Physical Science
To explore the different properties of matter than enable mixtures to be separated. To demonstrate the separation of mixtures through filtration and evaporation.
- How can mixtures be separated?
- Why are the physical properties of matter important in separating mixtures?
- What occurs during filtration of a mixture?
- What occurs during evaporation of a mixture?
Different types of matter can be combined to form mixtures. Thanks to the physical properties of matter such as size, shape, and density, mixtures can also be separated back into their different kinds of matter. One way mixtures can be separated is through filtration. Filtration is the passing of matter through a filter to separate larger particles. Another way mixtures can be separated is through evaporation. Evaporation is the process where the liquid in a mixture changes to a gas leaving other solid particles behind.
- Coffee filters
- Stir a spoonful of sand into a half a cup of warm water. What happens to the sand? Record your observations.
- In another cup, stir a spoonful of salt into a half a cup of warm water. What happens to the salt? Record your observations.
- Stick the straw into the salt water mixture. Take a small sip. What does it taste like? What does this prove about the salt?
- Look at the sand mixture and the salt mixture. How are the mixtures different? Record your observations. Do you think the mixtures can be separated?
- Place a coffee filter over one of the empty cups. Carefully and slowly pour the sand mixture into the filter. Record your observations. What happens to the water and the sand?
- Try the same filtering method with the sand water. What happened? Taste the “filtered” salt water again with a straw. What do you notice about the taste?
- Pour a small amount of salt water into another cup. Set it on a windowsill and observe it every day for a few days. Record your observations. After the water is gone, what is left behind?
Terms/Concepts: Matter; Mixture; Particles; Filtration; Evaporation
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