Investigations were carried out in a science lab to explore the topic of chemical and physical changes.Investigation AStep 1. Add 5 tsp. salt to 100 ml warm water and stir until most or all of the salt is no longer visible.Step 2. Heat the salt solution on a burner until only a white solid remains.Investigation BStep 1. Mix 10 tsp. white sugar into 100 ml water and stir until most or all of the sugar is no longer visible.Step 2. Heat the sugar solution on a burner until the solution thickens and turns brown.
Jenna took an open bowl of leftover mashed potatoes from the refrigerator and noticed a difference in smell. She determined that chemical changes occurred since the potatoes were first placed there.
Which event always involves a chemical change?
Which statement best describes what happens during a chemical change?
A scientist is examining an unknown solid. Which procedure would most likely help determine a chemical property of the substance?
Justin is making a snack. He toasts a piece of bread and spreads peanut butter and jelly on it. Then he cuts an apple into several slices and adds these to his plate. Next, Justin mixes a scoop of lemonade powder into a glass of water, mixes it, and adds ice.
Which laboratory activity involves a chemical change?
Henry mixed salt and water together in a cup until he observed a clear solution. He measured the mass of the solution. Then he placed the cup outside for several sunny days during the summer. After a week, he observed that only solid salt remained in the cup and the mass had decreased. Henry concluded that a physical and chemical change occurred in this investigation.
Which statement best describes a physical change?
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