SSC
CHEMISTRY
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Physical Change
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Chemical Change
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Either A or B
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None of the above
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Detailed explanation-1: -You forgot to dry the bread knife when you washed it and reddish brown spots appeared on it. Chemical because water + metal = rust. A new substance was formed.
Detailed explanation-2: -Rusting is an example of a chemical change.
Detailed explanation-3: -It is a chemical change. The transformation of flour into gluten chains creates a new substance with different properties, and an altered chemical composition. The gluten chains cannot become flour again. It is an irreversible change.
Detailed explanation-4: -Answer and Explanation: Toasting bread is a chemical reaction because the heat applied to the bread causes a process called the Maillard reaction. This is a chemical reaction that causes the browning of food when cooking.