In a thermostat, what property of the bimetallic coil allows it to contract and expand?

The coil is made from two different metals bonded together. When the temperature changes, they expand or contract by different amounts because their thermal expansion properties differ. This unequal movement bends the coil, allowing it to expand or contract as the thermostat responds. Therefore, the correct choice is “The two metals absorb different amounts of thermal energy.”

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