Four Days of Physical Science in a Fifth Grade Classroom

5-PS1-3. Make observations and measurements to identify materials based on their properties. [Clarification Statement: Examples of materials to be identified could include baking soda and other powders, metals, minerals, and liquids. Examples of properties could include color, hardness, reflectivity, electrical conductivity, thermal conductivity, response to magnetic forces, and solubility; density is not intended as an identifiable property.] [Assessment Boundary: Assessment does not include density or distinguishing mass and weight.]

Learning Targets 1. I can explain what a physical property is and give examples of different physical properties. 2. I can explain why a certain physical property is intensive or extensive. 3. I can measure the physical properties of different substances and record the results to use later. 4. I can use information about the physical properties of different substances to identify unknown samples.

During the past few days we have- Measured the color, mass, volume, viscosity (timed marble drop in graduate), temperature, how well salt dissolved in sample, and temperature of several liquids. Used the results of our test to identify unlabeled samples the next day. Discussed what properties are helpful in identifying substances. Discussed what properties are the same for all samples of a substance and what properties change depending on the sample size. Sorted samples of different plastics by color and ability to float. Sorted samples of different metals by color and magnetism.

Today’s lesson is an activity intended as a summative assessment of 5-PS1-3. Each table group has an “iPad/iPhone microscope. We will show you how to use it to study and photograph samples.

Once your group understands how to use the microscope get a small sample of both salt and sugar crystals from the materials table. Observe each sample under the microscope at low and high power. Record any observations about crystal shape, size, color, transparency and any other properties your team believes might help them identify the substance if you were given an unknown sample. You can also take images.

After your team has made all the observations they need of the known salt and sugar samples they should return to the materials table to collect a sample of the unknown substances in container “A” and “B”. Observe each sample under the microscope. Then select what is in each sample from the choices below. The sample is salt mixed with an unknown second substance. The sample is half salt and half sugar. The sample is 4 parts salt to 1 part sugar. The sample is 4 parts sugar to 1 part salt. The sample is equal amounts of sugar and salt mixed with an unknown second substance.

Sample “A” Sample “B”