Chemical ChangesNail Experiment Using “Talk Moves”andClaim, Evidence, Reasoning, Rebuttalfor Argumentation in Science
Students will first use the strategy called “Talk Moves” to discuss the question: What will happen to a pure Iron nail if exposed to a moist, wet environment? (DO NOT GIVE THE STUDENTS THE CORRECT ANSWER UNTIL AFTER THE EXPERIMENT) The correct answer is the nail will gain mass. Directions: Teachers go over “Talk Moves” and Positive Interactions Sheet with the students before you begin. Explain to your students why positive interactions are important when discussing science concepts. (Use sheets 3 and 4 to review why and how we use Talk Moves.)
Students will then set up an experiment to discover which nail will collect more rust. A nail put in water, salt water, vinegar, and coke. (Make sure to use ungalvanized/uncoated nails, nails for cement will work. It is difficult to find pure iron nails but steel uncoated nails will work or you could purchase iron strips.)
You could also set up a demo in the front of the room using galvanized nails or zinc coated nails or copper screws to use as a comparison with the student's results. (They will not rust quickly)
Day 5 or later:
Students will observe and weigh the final mass of their nails. They will use the strategy Claim, Evidence, Reasoning, and Rebuttal to discuss which nail should have accumulated the most rust. Included with this is a short reading excerpt which explains how iron rusts. Nails should rust in salt water followed by water, then coke and finally vinegar. (Depending on the oxygen from the water or solution and the oxygen from the atmosphere)
Students will use the reading excerpt and the data from their experiment to write a C.E.R.R for their experimental outcome.
Go back to the initial inquiry question and use “Talk Moves” to discuss why the nail had gained mass.
-TALK MOVES INQUIRY QUESTION SHEET
-WHY USE TALK MOVES SHEET/POSTER
-TALK MOVES STUDENT GUIDELINES SHEET/POSTER
-RUSTY NAIL EXPERIMENT
-RUSTY NAIL Claim, Evidence, Reasoning, Rebuttal Sheet
-C.E.R.R. Blank Template
NEXT GENERATION SCIENCE STANDARD:
PS-1: Matter and Its Interactions
Conduct an investigation to determine whether the mixing of two or more substances results in new substances.
Argument from evidence.
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