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Physical Science
The Three States of Matter
To introduce the three states of matter, students examine several models that illustrate the characteristics of particles in each state.
You can also make a demonstration model using balloons and large trash bags. Blow up several balloons and pack them into a large trash bag until the bag is full. This is a model of a solid. The students can observe that the shape of a solid stays constant and there is not much room between the particles so they aren’t able to move. After you create the bag to represent a liquid, you can show the students how because the particles have more room to move around, the bag can be shifted into different shapes much like a liquid can take the shape of its container. This can be demonstrated by allowing the students to try putting the bag into a square box or round trash barrel.
Heterogeneous, homogeneous, and solutions:
To create heterogeneous mixtures, students make trail mix or mix various small items together to illustrate how mixtures can be easily separated.
To create homogeneous mixtures, students can make a powdered drink mix with water to illustrate how a homogeneous mixture is not easily separated. During this activity, students can feel when the crystals seem to disappear in the water, at this point they have entered into solution. Students can taste the plain water and then the solution to describe differences. Safety Note: Remember lab materials should never be tasted unless directed by instructor.
The concepts of diluted and concentrated solutions can be experienced by adding more or less of the solute (the powdered drink mix). Salt and water provides an easy way to show that some solutions can be separated by evaporation. The students can tactually observe the crystals dissolving. If the salt solution is left to evaporate, the student can then feel the crystals that have reformed in the container and note that the water has evaporated.
Separating a sand/salt mixture is another common experiment that students with visual impairments can do with few adaptations. Present the students with a mixture of sand and salt and ask them to separate the salt and sand. Many students will use their fingers to separate the mixture. However, the student "in the know" will add water to the mixture and stir. After lining a funnel stand with filter paper, the student pours the mixture into the funnel. The sand stays in the funnel, and the water filters out. But where is the salt? Following the evaporation process described above, the salt reappears separated from the sand! Low vision students may notice that as the salt re-crystallizes it may look tan or brown. This is due to impurities from the water being trapped inside the salt crystals.
"Mystery Box Activity": Qualitative vs. Quantitative Data
Students often have a difficult time differentiating between the types of data or observation asked for in a question. We start with the basic definitions of qualitative and quantitative data. Quantitative data is expressed in numbers and comes from measuring or counting. Qualitative data is descriptive and involves data that usually cannot be counted.
To make qualitative observations, we discuss our senses and use them to describe everyday objects (spoons, gloves, pencils, soda cans, etc.). After practicing with qualitative observations, give each student a box containing ten items. Each student needs to have the same ten items. For students with low vision, we ask them to close their eyes. Students take turns describing an item with one-word descriptors until another student can guess which item from their box the student is describing. To make quantitative observations, we use talking scales, talking thermometers, and talking tape measures to collect data. Then the students record the number data in a chart. Students can then practice ordering the items by size, mass, temperature, etc.
Building a basic Serial Circuit
Every student does a unit on electricity and circuits at some point in his/her education. For visually impaired students, many of the same material and activities can be used. Some adaptations and modifications that will assist a student with a visual and/or other impairments to build a circuit include: the use of Velcro to stabilize each component atop a template board with Velcro patches where the components go, the use of traditional single blade switches where the open/close action is more readily comprehended tactually than other forms of switches, and the use of Magna lead wires where the connections at the end of the wires are magnetized and thus easier to connect than standard alligator clips and the like. Standard electric motors and batteries are generally safe for any student to use.
Materials for serial circuits
11” x 9” white cardboard template with 4 black Velcro patches
Basic circuit components (motor, 1.5v AA battery, battery holder, single-knife switch) with lead wires attached to each with alligator clips on ends and Velcro on underside of each. The motor will need to be fastened to a sturdy base of some sort and then Velcro placed on underside of the base.
Activities using the circuit set-up
One activity our students enjoyed was making fans out of Braille paper and taping them to a wheel which fit on the motor. The air movement created by the fan when the motor was on added another sensory dimension to the activity.The circuit can be used to examine conductors and insulators. Students can break the circuit at any point, place various materials between the alligator clips and observe whether the motor runs or not. We have used metal objects like empty soda cans, strips of copper, as well as insulators like wood blocks and plastic and glass containers.