Activity 7A.7 (Lab Activity)
Assessment: A Challenging Separation
Note to Teachers: There is no corresponding student version of this separation activity on the site. This is an in-class activity.
|Lesson Overview||This activity combines several types of separations into a single separation activity. It can be used to assess what students have learned from the other separation activities. In particular, before doing this challenging separation, you should have completed the in-class lab activities 7A.1 (Separating Marbles), 7A.3 (Separating Plastic and Metal Beads), and 7A.5 (Magnetic Separation) with students. Since the mixtures will contain more than two components, students will need to use more than one method to achieve separation. Student groups must choose which equipment will separate their particular mixture.|
|Learning Objective||Students will apply what they’ve learned about separation techniques, namely, that they are based on differences in properties of the substances that are mixed together. They will use their problem-solving and logical-thinking skills.|
|Lesson Concepts||Different physical properties of substances in a mixture allow for separation techniques that use the varying physical properties (e.g., particle size, density, magnetic attraction).|
Per lab group:
Students should wear safety goggles. Students should be cautious using glass materials (marbles and jars).
Any skills learned in the previous separation activities (7A.1 through 7A.6).
After the pre-lab review of separation techniques, this activity should take 1520 minutes to carry out.
|Student Ability Level and Grouping||
This activity may be done by middle school students working in groups of two or three.
Examples of student procedures:
Step 1: Pour the mixture into an aluminum pie pan and use a magnet to extract the steel beads. [property: magnetic attraction]
Step 2: Put the remaining mixture into a container of water so that the plastic beads float to the top and can be scooped off. [property: density]
Step 3: Use a container apparatus as a filter to separate the large marbles from the small marbles. [property: particle size]
Step 1: Pour the mixture into a container filled with water. The plastic beads should float to the top and be scooped off. [property: density]
Step 2: Drain the water off the remaining mixture and pour the mixture into a container apparatus (filter) to separate the large marbles from the small marbles and the steel beads. [property: particle size]
Step 3: Pour the steel beads and small marbles into an aluminum pie pan and use a magnet to extract the steel beads, leaving only the small marbles. [property: magnetic attraction]
Students should describe how their method of separation is an application of the basic idea behind separating mixtures on their Investigation Record Sheets.