SME
Grade 7 Science · Problem type
Changes that heat up or cool down
Use this for “Which reaction could warm a meal without a flame?”
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Does it give out heat or take heat in?
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Assumptions
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Feel the container: warmer means energy left the reaction, cooler means it went in.
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Designers choose the reaction and the amounts to reach the temperature they need.
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Dissolving is a physical change, but it can heat up or cool down too, as in a cold pack.
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Chemical change or physical change?
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Photosynthesis and cellular respiration
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Chemical change or physical change?
Use this for “Is water changing into steam a chemical change?”