Name: Date: Chemical Changes Physical Changes
Breaking Burning Chemical change Condensation Condensing Drying Eroding Evaporating Freezing Grinding Melting Physical Change Rotting Rusting Sublimation Changes - Page 2
THE SITUATION THE SITUATION You have been asked to help purify some contaminated water samples for Green youth. There are over 250 abandoned mining sites in Nunavik. To help you with this problem, you are exploring and investigating specific parts of matter. Today you will be looking at physical and chemical changes in matter. Physical Change A changes in the state of matter. Chemical Change The result of new substances taking on their own properties.. You will be given 6 procedures to follow. You are free to make changes if you think the procedure can be improved upon. Remember to note any changes you make Clean-up has started in several sites, however, much more work still needs to be done. Changes - Page 3
EXPERIMENT Experimental Method I observe. I develop a research question. I define the variables. I experiment. I collect the data. I analyze my results and present them. I observe:. There are different ways you can change things. For example, you can tear up a piece of paper into small pieces. What remains is still paper. You have changed the way the paper looks; however, you have not made a new substance. This is a physical change. If instead you burn the paper, what is left? What is left is no longer paper. In this case the substance is changed. This is a chemical change. Changes - Page 4
TEACHER DIRECTED NOTES Changes Physical Change: EXAMPLES: A physical change is. Chemical Change: EXAMPLES: Signs that a chemical change has taken place: A Chemical change is. Changes - Page 5
EXPERIMENT I develop a research question: Can you determine if a physical or chemical change occurred? I define the variables: You will use a checklist to determine if a physical or chemical change has taken place. Changes - Page 6
EXPERIMENT I Experiment Procedure: Below is the proposed procedure for this experiment. If you change the procedure, make sure you note your changes. Experiment 1: Water 1. Fill a porcelain dish with 5 ml of water. 2. Place the dish on a hot plate. 3. Turn on the hot plate to boil the water in the beaker. 4. Record all your observations during the experiment. Changes - Page 7
EXPERIMENT I Experiment Procedure: Below is the proposed procedure for this experiment. If you change the procedure, make sure you note your changes. Experiment 2: Salt 1. Place a weigh boat on a balance and press the zero button. 2. Measure 0.5-g of salt in the weigh boat. 3. Poor the salt from the weigh boat into a beaker. 4. Add 50 ml of water to the beaker. 5. Record your observations during the experiment. Changes - Page 8
EXPERIMENT I Experiment Procedure: Below is the proposed procedure for this experiment. If you change the procedure, make sure you note your changes. Experiment 3: Sugar 1. Place a weigh boat on a balance and press the zero button. 2. Measure 0.5-g of sugar in the weigh boat. 3. Poor the sugar from the weigh boat into a porcelain dish. 4. Place the dish on a hot plate. 5. Turn on the hot plate to heat the sugar. 6. Turn off the heat when the sugar caramelizes. 7. Record your observations during the experiment. Changes - Page 9
EXPERIMENT I Experiment Procedure: Below is the proposed procedure for this experiment. If you change the procedure, make sure you note your changes. Experiment 4: Alka-Seltzer & Vinegar 1. Measure 20-ml of vinegar in a graduated cylinder. 2. Pour vinegar into the 125-ml flask. 3. Place half an Alka-Seltzer tablet in the flask with vinegar. 4. Record all your observations during the experiment. Changes - Page 10
EXPERIMENT I Experiment Procedure: Below is the proposed procedure for this experiment. If you change the procedure, make sure you note your changes. Experiment 5: Chalk 1. Place a piece of chalk in paper towel. 2. Lightly hammer the chalk in the paper towel. 3. Carefully unwrap the paper towel and record all your observations during the experiment. Changes - Page 11
EXPERIMENT I Experiment Procedure: Below is the proposed procedure for this experiment. If you change the procedure, make sure you note your changes. Experiment 6: Wooden Splint 1. Break off approximately 2 cm of the wooden splint. 2. Light the wooden splint with a match. 3. Place the burning splint into the beaker. 4. Record all your observations during the experiment. Changes - Page 12
EXPERIMENT RESULTS (I collect my data) Use this page to record the results and what you observed during your experiments. Changes - Page 13
Water Salt Sugar Alka-Seltzer & Vinegar Chalk EXPERIMENT Wooden Splint RESULTS (I collect my data) In the table below record the results of your experiments by placing an X for No and a for Yes. Was a new substance formed? Was there a colour change? Was there any smell? Was the change easily reversible? Was heat given off? Was light given off? Can the transformed substance still be used for its original purpose? Was a gas formed? Changes - Page 14
ANALYSIS I analyze my results and present them. State if a physical or chemical change occurred in each of the experiments you performed by circling the correct answer, and then justifying your reasoning. 1. Water: Physical Change or Chemical Change 2. Why did you pick that change? 3. Salt: Physical Change or Chemical Change 4. Why did you pick that change? Changes - Page 15
ANALYSIS 5. Sugar: Physical Change or Chemical Change 6. Why did you pick that change? 7. Alka Seltzer & Vinegar: Physical Change or Chemical Change 8. Why did you pick that change? Changes - Page 16
ANALYSIS 9. Chalk: Physical Change or Chemical Change 10. Why did you pick that change? 11. Wooden Splint: Physical Change or Chemical Change 12. Why did you pick that change? Changes - Page 17
ANALYSIS 13. Using your experiments as examples, what are the signs that a physical change occurred? 14. Using your experiments as examples, what are the signs that a chemical change occurred? Changes - Page 18
REFLECTION ACTIVITY 1. Classify the terms from the Word Wall, as words describing physical or chemical changes by writing them under the appropriate heading. PHYSICAL CHANGES CHEMICAL CHANGES 2. Experiment 1: Water. If you were to repeat this experiment, would you change the procedure? Explain why or why not. Changes - Page 19
REFLECTION ACTIVITY 3. Experiment 2: Salt. If you were to repeat this experiment, would you change the procedure? Explain why or why not. 4. Experiment 3: Sugar. If you were to repeat this experiment, would you change the procedure? Explain why or why not. Changes - Page 20
REFLECTION ACTIVITY 5. Experiment 4: Alka-Seltzer & Vinegar. If you were to repeat this experiment, would you change the procedure? Explain why or why not. 6. Experiment 5: Chalk. If you were to repeat this experiment, would you change the procedure? Explain why or why not. Changes - Page 21
REFLECTION ACTIVITY 7. Experiment 6: Wooden Splint. If you were to repeat this experiment, would you change the procedure? Explain why or why not. Changes - Page 22
REVIEW QUESTIONS Review Questions Read the sentences below. Do they describe chemical or physical changes? If you are uncertain, explain why. 1. A white substance exposed to light turns dark. 2. A colourless liquid disappears when heated. 3. As a liquid is heated, crystals appear at the bottom. 4. A colourless liquid turns yellow when heated. 5. A flash of light occurs. 6. Two liquids are mixed and their temperature rises by 10 C. Changes - Page 23
REVIEW QUESTIONS 7. Two liquids are mixed and become milky. 8. A liquid is cooled and a solid forms on the bottom of the beaker. 9. A bar turns black when heated. 10. When a bar is heated, the room fills with choking fumes. 11. A sweet substance is stirred into a colourless liquid. The liquid remains colourless but tastes sweet. 12. A blue solid is dropped into water, and the water turns blue. Changes - Page 24
CONSOLIDATION Consolidation 1. Which of the following statements are examples of chemical or physical changes? Explain. a. Changing a gold bar into wire - Explain: b. Frying meat - Explain: c. Bleaching your hair - Explain: d. Cutting up string - Explain: e. Shooting off fireworks - Explain: f. Squeezing a lemon for juice - Explain: g. Rainwater evaporating from the ground - Explain: h. A burning cigarette - Explain: i. Sublimation - Explain: 2. Which of the following are chemical changes? a. 1 and 3 b. 2 and 4 c. 1, 3 and 5 d. 1, 2, 3 and 5 ANSWER: 1. A gas being released 2. An increase in volume 3. A change in colour 4. The temperature changes 5. Light produced Changes - Page 25
CONSOLIDATION 3. Which of the following statements shows two (2) examples of physical changes? a. A nail rusts, paint falls off the side of a boat b. Water freezes, wood burns in a fire c. Snow falls, photosynthesis in plants d. Mud settles to the bottom of the pond, sugar added to coffee 4. Give four possible signs that a chemical change has occurred. a. b. c. d. 5. State whether each item is an example of a physical or chemical change. Use C for a chemical change and P for a physical change answers. a. Dissolving salt in water b. Leaves changing colours in the fall c. Mercury rising in a thermometer d. Breaking glass e. Cutting paper f. Burning wood g. Sanding a piece of wood h. Boiling water i. Dough rising when baking bread j. Freezing water 6. True or False. a. The new substances made in a chemical reaction have new properties. b. All physical changes involve taking in or giving off energy. c. A physical change makes new substances. d. Melting ice is a chemical change. e. In a chemical change there is never a change in colour. Changes - Page 26
GOING FURTHER Going Further Changes card game: Use the cut-outs on the last two pages of this booklet to play the sorting game. You can complete this activity alone or with a partner. Here are the instructions. - There are 15 cards and two titles. - Cut out all 17 pieces. - Place the two title pieces on a flat surface. Make sure there is at least 10 centimeters of space between the two titles. - Take the cards one at a time, look them over and place them under the appropriate title. - At the end of this activity you might be asked to share your groupings with your classmates. This can be done orally or on the Smartboard. Changes - Page 27
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