Elements, Mixtures and Compounds

Transcription

1 Elements, Mixtures and Compounds Standards Topic VA-SOL.SC.PS.2 STANDARD: The student will investigate and understand the basic nature of matter. Key concepts include B. elements, s, s, acids, bases, and salts; LESSON PLAN OUTLINE Title: Elements, Mixtures, and Compounds Continued Related Concepts: Element Mixtures Compounds Organic s Inorganic s Instructional Objective(s) Students will define: s, s, matter, substance, element, homogeneus, heterogeneus, colloid, suspension, and solution Students will distinguish between s and s Students will distinguish between elements and s Students will describe how to determine whether a substance is an element,, or Materials & Resources Engage It's a Mixed Up World: ans/mixedupworld.pdf Used for the graphic organizer in the Explain section and as the basis of the activity in the Expand section of this lesson Elements, Mixtures and Compounds Beads: ompoundbeads.doc This lesson plan provided the basis for the activity done in the Explore section of this lesson. Students will answer the following Bellringer question: "Besides as states of matter, are there any other ways to classify matter? If so, how? If not, why not?"

2 Explore Bead Sort In this section of the lesson, students will sort beads to help them understand the differences between elements, s and s. Before beginning the lesson, you will need to prepare the following class set: For one complete sample set, fill nine petri dishes and label the lids as described in the table below. A Sharpie works well for the label, and a piece of clear tape over the writing will make the label more permanent. Use a dab of super glue to affix the lids securely. Dish Label Dish Contents Classification R Red beads only element B Blue beads only element Gn 2 Green beads, wired in pairs diatomic element BGn 2 P PGn R 4 Gn RGn + Gn 2 R + P + Gn 2 B + R one blue bead, two green beads, and a pearl wired together a pearl wired to a green bead four red beads wired to a green bead Some green beads wired in pairs, as well as several pieces consisting of a red bead wired to a green bead Loose red beads, loose pearls, and green beads wired in pairs Loose red beads and loose blue beads During the lesson, the students will be led in the following steps: 1. Divide class into pairs of students. Instruct students not to open the dishes. 2. One student from each pair should come forward to obtain a bag of samples. 3. Ask students to sort the dishes into three groups based on similarities in the contents of the dishes. Emphasize that when students disagree with their partners about the classification, they should discuss their ideas until a consensus is formed. 4. As a class, present and discuss the different ways that the students sorted the dishes. Ask the students to explain why they sorted the dishes the way they did.

3 Explain Students will be led in a discussion of the ideas related to elements, s and s. As the discussion moves forward, students will be led in completing a graphic organizer (tree diagram) of the information being discussed in class. Ask students what elements, s, and s we encounter everyday. Key Vocabulary: Matter Substance Compound Element Compound Homogeneus Heterogeneus Colloid Suspension Solutions Extend MATERIALS NEEDED: It's a Mixed Up World Examples of elements (aluminum and copper), s (salt, water, ammonia, and sugar), and s (oil and vinegar salad dressing, cake, vinegar, and glass) Safety Goggles Alum (dispense in salt shakers or with a measuring spoon) Filter materials (gauze pads, cotton, coffee filters, fabric, cheese cloth) Sand Aquarium filter charcoal Styrofoam cups (for layering filter materials) Clear cups or jars for retrieving treated water Jug of water with soil/mud added Waste collection bucket Any other reasonable request Preparatory Directions: Assemble the required materials. Check school policies on working with solutions to see whether safety splash goggles are required. Prepare untreated water sample (muddy water). Put together activity kits for each group: alum, 1 styrofoam cup, 1 clear cup, and adequate amounts of each filtering option. Allow 1 teaspoon of alum for 1 cup of dirt water (A 53 gm jar contains about 15 teaspoons). Wash aquarium charcoal to avoid increasing turbidity of filtered water. Activity Directions: 1. Show students an example and have them identify it as an element,, or and explain their reasoning. (Either pass

4 examples around the room or display where each can be clearly seen.) 2. Discuss or clarify categorization of examples if needed. 3. Discuss the water purification process. The source of drinking water for many communities is river or lake water. The untreated water contains a variety of suspended and dissolved materials. 4. Divide the class into working groups of three. Explain that they will be working together to unmix a which will result in cleaner water. 5. Provide each group an activity kit and explain that they can construct their filter out of any materials they wish. 6. Have students discuss how s can be separated into pure substances in their small groups. Students should use this information to help them separate the muddy water. 7. Punch holes in the bottom of the styrofoam cups to allow water drainage. Holes don t need to be too large or too small remind students to use ONLY the tip of the ink pen/pencil (not the entire object) to make many holes. 8. Once a group has the filter constructed provide them with a cup of untreated water and instruct them to add a small amount of alum and stir observe and record observations. Repeat until coagulation occurs. ***SLOWLY pour the untreated water through their filter.*** 9. Each group should produce: their ideas about how s can be separated, how they layered their filter, and their analysis of their filter (what should they have done differently) 10.If time: have teams compare the clarity of their samples after they finish. Discuss why some samples ended up clearer than others. Discuss if this activity would be possible with s or elements. Evaluate Students will write an exit pass which includes: 3 things they learned 2 things they are confused about 1 question they still have Plans for Diversity Students will be placed in heterogeneus groups which each have a mixed ability level of students. Notes will be written as students write them. If necessary, students will be given a copy of the notes rather than writing them themself.

5 Connections This lesson directly follows the set of lessons on the states of matter. Because of this, students are able to begin to see that there are multiple ways to classify matter rather than just into 3 states of matter. After this lesson, the students will learn another method of classifying matter, acidity.