The atoms in a sample are close together but can slide past one another. As the atoms lose energy, they move slower. The atoms become locked in place because of attractive forces between them. Which change of state is taking place?

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The chemical reactions lab we did is typically called a "copper plating lab,  because the acid solution cleaned the pennies and made the copper look shinier;   the acid solution cleaned the paperclips and made them look like pennies;   &   the copper from the pennies was removed, and then added to the paperclips.