Earth Materials Module Activity Two: Scratch Test Grade Level: 3& 4 Lynn Risenhoover		Themes: Rocks and Minerals have identifiable characteristics. Unit themes: Pattern, Structure, Interaction, and Change Lesson themes: pattern, structure
Science Thinking Processes: Observing, Communicating, Comparing, Organizing		Science Concepts: Earth material Hardness of minerals Mineral Property Rock
Unit Essential Questions: What are the characteristics and properties of the solid materials that form the earth? (rocks and minerals)? Unit Guiding Questions: What are rocks made of? What are the physical and chemical properties of minerals? How can we identify minerals? Lesson Essential Question: How can we identify minerals using the scratch test? What is the property we test for when we use the scratch test?
Specific Objectives: Explore the properties of a group of minerals, Investigate the hardness of minerals, Organize minerals according to hardness.
Standards addressed (EALRs)
1.1. Properties: Understand how properties are used to identify, describe, and categorize substances, materials, and objects and how characteristics are used to categorize living things. 2.1. Investigate Systems: Develop the knowledge and skills necessary to do scientific inquiry.
Instructional Materials Needed (include handouts, overheads, etc.) For each group of four: 2 ceramic tiles, 2 pieces of chalk, 2 jumbo paper clips, 2 pennies, 1 Foss plastic tray, 2 hand lenses, scratch paper, 4 student sheets called Earth Materials Notebook pages 6-8. For the Class: 4 containers labeled 1 through 4, Mineral Samples: 8 calcite, 8 quartz, 8 gypsum, 8 fluorite, 1 large magnifying lens, 1 mineral identification sheet. Prepare a sample mineral set using a copy of the Mineral identification Sheet to be used as student reference sheet. Prepare: In each container place minerals as follows: 1-Calcite, 2- Quartz, 3- Gypsum, 4- Fluorite			Room Arrangement? Arrange tables so students participate in groups of four. Set up a material station in a convenient location where the Getters can get to the materials easily. Group Roles: Assign numbers to each member of the group. 1. Getter: responsible for materials, gets and returns materials, makes sure all materials are returned, and goes to teacher for additional information if needed by group. 2. Starter: is the first to begin experiment, supervises assembly of material, sees that all members of the group have equal opportunity for involvement. 3. Reader/Reporter is responsible for seeing that everyone begins with the same information and understands the task, reads instructions, reviews record sheets out loud to the group, summarizes findings and reports to the class. 4. Recorder: is responsible for recording all important data and observations.
Accommodations: ELL students: Vocabulary will be made available to ELL students prior to the lesson. Students will be put in groups with more advanced ELL students if possible, otherwise grouped appropriately with students that would be willing to help interpret. (work sheets are written in Spanish and English). ELL students will given learning logs so they can write in their own language, or draw thoughts, record vocabulary and other thoughts they wish to retain and reflect on later. Students with Special Needs will be grouped and be given roles appropriately.
Time	What the teacher does:			What the students do:
e.g. 5 min. 3 min 5 min 1 min 3 minutes 3 min 3 min 5 min 3 min 3-5 min 3- 5 min 5 min 3 min	Pre-Assess
	Part one: Observing Properties 1. Reflect on previous mock rock activity: · Ask students to raise their hands if they remember properties of rocks. (color, shape, texture). · Raise your hand if you can remember the difference between rocks and minerals. · Perhaps children would like to share the minerals they are most familiar with. (write down a list) 2. Tell them that today they are going to work only with minerals. Describe a Geologist’s job. Identification: · Raise your hand if you know how a Geologist might identify a mineral. 3. Distribute minerals 4. Observe Raise your hand if you think you know what a geologist does first when they try to identify a mineral. Working in pairs within your group using worksheet page 6 list properties of minerals.  Part 2: Scratch Test 6. Discuss mineral identification Now that we have had time to list the properties of these minerals work with your partner for one minute and try and figure out which mineral is quartz. Be prepared for an answer for I will call on someone to tell us what they think. There are three To four minerals that have similar properties to quartz. (hard and white) .7. Introduce Scratch Test: Explain that because minerals may have similar properties geologists have designed tests that help them identify a mineral. They test the hardness of the mineral. Even though all minerals are hard, some minerals are harder than others. Each mineral has a characteristic hardness and because of this minerals can be organized (seriated) in order of hardness. By looking at the property hardness, geologists gain another clue to help them identify the mineral. 8. Demonstrate the Technique Tell the students that they will use three tools to help them determine the hardness of the minerals- a paper clip. a penny, and their own fingernail. Explain that they will start with the hardest tool, the paper clip. Show the students the scratch test technique. · Scratch a piece of chalk or tile with the paper clip · Rub off dust or possible mark · Use hand lense to check for scratch. 9. Test to see which is harder chalk or tile. Ask pairs to demonstrate which is harder the chalk or the tile. Use popsicle sticks to ask student to report findings after a minute. Ask students to share findings.( tile could not be scratched) 10. Look for Quartz Write Quartz on the board. Tell students that this is the first mineral they are to identify using the scratch test. Quartz is the hardest mineral of the four. It is the only mineral of the four that cannot be scratched by a paper clip. 13. Look for Gypsum: Tell students to look for gypsum. Gypsum is the softest of the four minerals. So for this test they will use a fingernail, the softest of the three tools, to identify the gypsum. Gypsum is the only mineral of the four that can be scratched with a fingernail. 16. Look for calcite and fluorite by scratching with a penny Explain that the tool the penny is of medium hardness. It is harder than the fingernail but not as hard as a paper clip. The penny will scratch the mineral known as calcite but not fluorite.			Students will raise hands when they have an idea to share. Getters get a tray and a piece of scratch paper. Starters cut paper into pieces to fit into the four compartments. Each group member writes his or her number on one of pieces of paper.(above under roles) Then getters come up to get # 1 mineral sample, starters # 2, recorders # 3, and readers # 4. Place in appropriate compartment on tray. Students raise hand if have something to share. 5. Observe and List Mineral Properties Students working in pairs list (brainstorm) as many properties as they can for each mineral. Students talk quickly to partner to determine which mineral is quartz. Students listen and observe Getters get a piece of chalk, a tile, a hand lens, and a paper clip for each pair of students within a group. Students work in pairs to demonstrate which is harder the chalk or the tile. Students discuss with teacher their findings. 11.Scratch with paper clip: Students will work in pairs and begin testing each of the minerals to find out which one is quartz. Remind them that many classes will be using these specimens so try to make a small scratch and test an area that hasn’t been scratched already. 12. Identify Quartz Readers from each group report which mineral they found to be quartz. (#2) 14. Scratch with a fingernail Students perform the same scratch test on each of the three unidentified minerals, this time using their fingernail as the scratch tool. 15. Identify Gypsum Ask recorders from each group to report which mineral they discovered is gypsum. (# 3) Have getters get two pennies for their groups. Students will test the two unidentified minerals. 19. Students make a chart. Using page 7 of the Earth Materials Workbook students will write in the names of the minerals in order of number and record the tests that were performed on each mineral Have students fill in the blank spaces based on the evidence already present on the chart. 20.Order the minerals by hardness You may want to let students figure this out for themselves. Add up the number of tools that were able to scratch each mineral, then put the minerals in order of hardness. Quartz, fluorite, calcite, gypsum 21. Clean Up Have getters bring the Foss tray with the minerals back to the materials station. They put each of the minerals in appropriate container, throw away labels. Have getters bring back rest of equipment..
time  5 mi	Closure plan (consider including reinforcement of learning, affirmations, glimpse at tomorrow-bridge)
	22. Interpret a New Chart of Minerals  Ask students to apply what they have learned to a new chart on page 8 of the Earth Materials Notebook.  Teacher tells students which tools can scratch each of the minerals.			Students fill out new chart and then put minerals in order of hardness. List hardest mineral first.
Formative Assessment.(s) [Are they getting it along the lesson?] Teacher walks among the groups during the lesson to listen to students to make sure they understand.  Before students begin next lesson in this unit teacher will ask students to reflect on the scratch test questions. I would have each student write an answer and turn it in. 1. Why do geologists use the scratch test? 2. What property are geologists focusing on when they do the scratch test? 3. Neither diamond nor quartz could be scratched with the hardest tool, the paper clip. What could you do to find our which was harder?
Summative Assessment [Did they get it?] – end of lesson or unit Foss has hands on, pictorial and reflective question assessments that can be used at the end of the unit to see if the students understood the concepts. Hands on Assessment for the Scratch Test
Teacher reflections/caveats for those who use this lesson:
Web resources used/investigated with suggestions/comments regarding these sites:  Full Options Science System (FOSS). 1995. Earth materials. Delta Education