Properties of Matter: Investigation 1 –
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This Investigation is designed to
- provide students the opportunity to explore the physical and chemical properties of elements and compounds,
- introduce students to several procedures that are used for the determination of the mass, volume and density of elements and compounds,
- prompt students to analyze differences and similarities between the properties of elements and compounds, and
- promote students discussion as to whether the properties they investigated can be used to differentiate elements from compounds.
Teacher Preparation for the Investigation includes the following. This preparation should be done prior to students arriving in the lab.
- Fill one 100 ml beaker with copper shot, a second with aluminum powder and a third with calcium carbonate. Label the beakers according to the following chart.
- Ensure that the teacher is the only person who knows the contents of each beaker. The teacher will reveal the contents to the students later in Investigation Two.
- For the following materials either create separate piles or separate into individual weigh dishes: chalk, copper foil, and aluminum foil.
- Label the piles or weigh dishes, according to the following chart.
- Put all materials at the distribution area.
- Divide the students into five cooperative groups.
Student Preparation for the Investigation includes having students gather the following materials. This preparation takes place on lab day after student groups have settled at their assigned lab tables.
Note: The materials are listed in students’ SDRs. They are also listed below for your reference.
- (1) triple beam balance
- (6) weigh dishes
- (1) 1000 ml graduated cylinder
- (1) marker
- (6) 2cm pieces of masking tape
- (1) pair of gloves for each student
- (1) m pair of goggles for each student
- (1) liter pitcher filled with 500 ml of water
- (1) plastic funnel
- (1) lab scoop
- (1) sample of unknowns A through F
- Explain to students that they will have access to six samples. The samples are either elements or compounds.
- Tell students that they will investigate the physical and some chemical properties of the samples in order to determine the identities of the samples.
- Explain to students that during the investigation they will need to determine the mass, volume, and density of the samples.
Note: If necessary, refer students to the Determination of Volume Using the Volume Displacement Method procedure, the Triple Beam Balance Equilibration procedure, the Triple Beam Balance Use and Operation procedure, and the Measuring Mass Using a Weigh Dish or Beaker procedure.
- Encourage students to reflect on the PreLab video as they move through the procedural steps.
- Explain to students that during the Experiment, every procedural step is important. If one step is skipped, data can become invalid. To help students keep on track, direct them to read each step thoroughly, complete the step, then check it off (Read it – Do it – Check it off).
- Direct students to complete procedural steps in their SDRs.
- Observe the properties of each unknown substance.
- Record: Write some of your observations of each unknown substance in Table A.
- Before obtaining the mass of each unknown substance, you must first zero your triple beam balance. If you need help, follow the steps in the Triple Beam Balance Equilibration procedure.
- Once your triple beam balance is zeroed, determine the mass of each unknown substance. If you need help, follow the steps in the Triple Beam Balance Use and Operation procedure.
- When measuring the mass of each unknown substance, you must place each unknown into a clean weigh dish and then place it on the triple beam balance.
- Label each weigh dish according to the unknown substance using the masking tape and marker. If you need help, follow these steps of the Measuring Mass Using a Weigh Dish or Beaker procedure.
- Measure 10 grams of each unknown substance.
Note: It may be difficult to obtain exactly 10 grams of each unknown substance. Therefore, record the actual mass of each sample in Table A.
- Record: Write your measurements in Table A.
- Measure: Use of the methods for measuring volume to determine the volume of each unknown substance. If you need help, follow the steps in the Determination of Volume Using the Volume Displacement Method.
- Record your measurements in Table A.
Let students know your expectations for clean up. Ask them to clean up.