Teacher Does Student Does Concept

Transcription

1 8 th Grade 5E Learning Sequence Teacher Does Student Does Concept Engage Yesterday we reviewed what Physical Properties of objects or different substances and experienced several different types of Physical Changes Prior knowledge of chemical and physical change Today, I going to conduct two different demos and ask you to decide whether they demonstrate a Physical Change or something different. * Place an ice cube in a large spoon and places the spoon over a lit candle until ice melts over the edge of the spoon. What type of change is this? Why? * show a glow stick to class. Is this a example of a Physical Change? Tell why? What causes this stick to glow? Write in notebooks, what is the difference between chemical change and physical change Explore #1/Explain #1 Use ipads or text book with partner to read and find out about chemical and physical change. Share ideas with class Write one clear statement in notebook about what is a physical Phase change; no new molecules formed, still water molecules). glow stick and it is activated when it is crushed. No, not sure Some might say chemical reaction Physical change can change appearance, but it is the same thing Chemical change changes chemically Share notes from reading; examples of chemical change (e.g.rust) and physical change (e.g. Physical change is when the Physical change is when the appearance of the matter changes, but it is still the same matter (e.g., Chemical change is when the matter chemically changes to produce a new

2 change and what is a chemical change Explore #2/Explain #2 We are now going to experience several different experiments to determine if the experiment is a chemical or physical change. Review procedures for each onewhich will also be posted at each center. The focus questions is: What type of change is this and what is your evidence? Set up a Data Table (see end of lesson) to record all observations, Before and After mixing, and record the physical properties for each of the reactants and products and list any evidences After the lab is completed, ask groups to share their results for each center using these prompts: Explain what the experiment involved; what were the physical properties before mixing; after mixing. What type of reaction do you think this was and why? appearance of the matter changes, but it is still the same matter (e.g., Chemical change is when the matter chemically changes to produce a new product different from the first matter work in partners/lab groups for each center record observations and determine if the reaction in physical or chemical and why note things in different stations like baking soda + vinegar =bubble being formed gas; plaster of paris + water = change in temperature in the bag; baking soda + calcium chloride = formation of precipitate Use their evidence to discuss whether it is physical or chemical product different from the first matter Chemical reactions can be identified by a change in color, production of gas, temperature change or the formation of a precipitate

3 Provide a challenge experiment and ask students to observe and determine what type of reaction was created Production of gas, temperature change, and color change make it a chemical change. Explain #3 Build a word wall from student reading and experiment In table groups, ask students to develop a definition of a physical change from their notes and experiment and write it on white board Refer to word wall; have they included academic vocabulary? Underline it. Have they included evidence for their definition? Have 2 groups share and determine the definition they like best Have the selected definition brought to the front of the class. Call on people to read each board, then ask the class to vote for the best definition Ask students to write that definition in their notebook REPEAT for CHEMICAL CHANGE Extend Use ipads to capture pictures of chemical or physical changes in our environment. Be prepared to share your pictures and explain why it is representative of a chemical or physical change. Have each group present Contribute words from their notebooks that they want to know more about and learn to use Create group definition Refine definition Select one to share with class Discuss ideas and vote Enter definition Write, vote on and enter a definition for chemical reaction into notebooks in partners, capture images Share image and evidence (e.g., leaf with photosynthesis is a chemical change leave is green, but changes color Definition, with evidence, for a chemical or physical change Chemical and physical changes can be observed in our environment

4 Evaluate Write a sticky note post it to define a chemical and physical change Write sticky notes with definition and examples ask students to turn back in their notebooks to the place where they had written their first definition of a physical and chemical change and compare it to the summary they have just written. Ask them to share how their understanding has changed as a result of their recent experiences. Better definition with example, evidence for the type of change At the end of the unit, have students use notebooks to write an informative essay comparing physical and chemical change. Write at least a 5 paragraph essay comparing physical and chemical changes, citing evidence for both, using experimental data, and information from the text. Writing meets the CCSS ELA Content Literacy in Science standards.

5 Data Tables EXPERIMENT #1 PHYSICAL PROPERTIES BEFORE MIXING PHYSICAL PROPERTIES AFTER MIXING TYPE OF REACTION/ EVIDENCE? Reactant A Reactant B Product(s)