[Q]: -  A photovoltaic cell is created with two layers of semiconductor material - The top layer are &#x27;doped&#x27; with impurities to allow a negative charge - The bottom layer are &#x27;doped&#x27; to allow for a positive charge - This produces an electric field that allows electrons to flow from negative to positve - Sunlight enters the cell - Energy from sunlight knocks electrons loose in both fields - This prevents the flow of electrons from negative to positive - Adding an external circuit allows the exchange to continue  What might be the last step of the process?
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[A]: Give the cells owner a flow of electricity.


[Q]: -  Water gets into cracks in rocks - The water freezes into ice - The cracks expand - Over time the rocks split  What might be the last step of the process?
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[A]: The rocks are now in smaller pieces.


[Q]: -  Electromagnet creates magnetic field with electricity - Conductive copper wire is wrapped around a piece of metal - An electric current gets introduced from power source - Flows through the wire - Magnetic field gets created in the wire - And the metal gets magnetized  What might be the last step of the process?
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[A]: When turned off it is no longer magnetic.


[Q]: -  Water is heated - The heated water evaporates - The salt is left behind - The evaporated water condenses on a cold surface - The evaporated water is collected - The process is repeated  What might be the last step of the process?
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[A]:
More salt is removed from the water.