Explore 2: Playing with Clay, Sand, and Silt

Transcription

1 Explore 2: Playing with Clay, Sand, and Silt Target Concept The mineral properties of soil (clay, sand, and silt) have different attributes. Addressed Standards SB-1 SB-2 Assessment Task Determine how clay, sand, and silt are different and similar to each other. Vocabulary clay sand silt sieve Materials per Student Student sheet, Playing with Clay, Sand and Silt, page 119 Crayons or colored pencils Materials, Station 1 2 sets of Sieves, see Preparation 2 small coffee cans (soup cans or wide mouth jars will also work) 4 rubber bands mesh (as found on an orange bag) or screen 2 pieces of cheese cloth, about the size of a coffee filter Coffee filters Old nylons Sand, silt and dry clay mixed together in a container 8 paper plates Materials, Station 2 4 hand lens Sand Silt Dry clay Microscope and/or blister scope if you have one Wipes Materials, Station 3 Large bucket (for wet soil to be dumped outside or saved for a later use ) Paper towels Wipes Sand 116

2 Silt Dry clay 2 cups of water Materials, Station 4 Bucket (for wet soil to be dumped outside or save for a later use) 2 full pitchers of water Dry clay Sand Silt 6 clear plastic hole punched cups (see preparation) 6 large plastic cups Wipes Paper towels 2 sets of measuring cups (graduated cylinders would be better if you have them) 2 sets of measuring spoons Preparation 1. Using the materials list provided above, set up 4 individual stations. 2. Cover all stations in newspaper for spills. 3. Collect 6 clear plastic cups. These are the disposable kind, tumblers. Punch 12 holes in the bottom of each cup using a tack. Put the cup into a larger clear plastic cup. The smaller cup should hang in the larger cup without its bottom touching. The silt, clay, or sand will go into the smaller cup. Water will be poured onto it. The water will then drain through the soil, through the holes, and into the bottom cup. This will be visible because both cups are clear. 117

3 3. To make sieves for Station 1 go to any hardware store and purchase 3 grades of screen. These usually come in cloth like rolls and are very cheap. You can usually get scraps and have them donated. The 3 grades would be outdoor screen, mosquito screen, and no-see-em screen. If a hardware store is not assessable, you can use a coffee filter, cheese cloth, nylon, the mesh of an orange bag, and mosquito net hat. To make the sieves you can either staple gun the screens into old frames, or you can rubber band them onto coffee cans or wide mouth jars. You can also purchase professional sifting sieves from any science education catalogue for anywhere from $20 to $60. Procedure 1. Divide the class into teams of 4 and within those, partners. Tell each group they will be moving together from station to station to conduct a series of soil explorations. At each station there are enough materials for 2 students to work together. Everyone will receive a student sheet to direct them through the activities. Each student is responsible for completing his/her student sheet. 2. Pass out the student sheets and allow students to follow the station directions. Encourage them to use pictures as well as descriptions. Generalize Ask the students the following: 1. Which station was the most interesting? 2. Which station was the hardest? 3. Which station told you the most about sand, silt, and clay? 4. How are clay, silt, and sand different from each other? 118

4 5. How are clay, silt, and sand the same? 6. Why do you think it would be important for people to understand the different properties of soil? (see Teacher Background) Assess Use the student sheets to asses understanding. 119

5 Playing with Clay, Sand, and Silt Assessment Rubric In Progress Towards the Standard Science Content Does not demonstrate the properties or the differences between sand, silt, and clay. Communication of Science Content Does not define the difference between sand, silt, and clay. Does not communicate the properties of sand, silt, and clay. Meets the Standard Follows directions. Clearly demonstrates the properties of sand, silt, and clay. Demonstrates the difference between a sand, silt, and clay. Clearly defines the difference between a sand, silt, and clay. Communicates the properties of sand, silt, and clay. Exceeds the Standard In addition to Meets the Standard: Tries new ideas at each station. In addition to Meets the Standard: Includes details. Soil is made of weathered rock. National Science Benchmark (From the full benchmark: Rock is composed of different combinations of minerals. Smaller rocks come from the breakage and weathering of bedrock and larger rocks. Soils is made partly from weathered rock, partly from plant remains, and also contains many living organisms. Only part of this benchmark was used to do its complexity.) From Benchmarks for Literacy from the American Association for the Advancement of Science. 120

6 PLAYING WITH CLAY, SAND AND SILT STUDENT WORKSHEET Name: Follow the directions for each station. STATION 1: SIFT Step A: Using the 3 different size screens, sift the soil. Begin with the screen with the smallest holes. Step B: Pour a handful of soil onto the screen. Gently swish it back and forth over a paper plate. Swish it until no more soil will sift through the screen. Step C: Move the same handful from screen to screen until you get to the one with the largest holes. Did some soil sift through all of the screens? Yes or No After you sifted through one of the screens, did the soil that came out look different than the soil before or after it? Yes or No Do you know which was the sand, silt, or clay? If so, why? BONUS: If you have time, rubber band a piece of cloth or a coffee filter to a can. See if it will also act as a sieve. If so, did it sift out small or large particles? Did it work as well as the screens? 121

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8 STATION 2: SEE AND FEEL Feel and look closely at the sand, silt, and clay. Describe and draw the sand. Describe and draw the silt. Describe and draw the clay. If you were to tell someone how to tell the difference between sand, silt and clay, what would you tell them? 123

9 STATION 3: MOLD IT Step A: Mix water with the sand, silt, and clay a little at a time until they are about as moist as cookie dough. Step B: Try to make a ball between your hands. Step C: Put all of the wet soils into the bucket when you are finished. Describe and draw the sand. Describe and draw the silt. Describe and draw the clay. If you were to tell someone how to tell the difference between sand, silt and clay, what would you tell them? 124

10 STATION 4: DRAIN IT Step A: Put sand in a small cup, silt in a small cup, and clay in a small cup. Step B: Use the measuring cups or spoons to pour the exact same amount of water onto each of the soils. (You decide how much water to use.) Step C: When the water stops dripping, take out the inside cup. Step D: Pour the water from the larger cup into the measuring cups. Step E: Measure the water. Step F: Pour all of the wet soils into the bucket when you are finished. How much water drained through the sand? How much water drained through the silt? How much water drained through the clay? If you were to tell someone how to tell the difference between sand, silt and clay in this station what would you tell them? 125