Acopper sheet is heated in a furnace until it melts. the hot liquid copper is then cooled until it becomes solid again. compare the mass of the copper before and after melting.

The principle of conservation of mass applies here, which states that mass can neither be created nor destroyed. Moreover, the changes taking place are physical changes, from the solid state to the liquid state and then back. Moreover, no reaction is occurring where mass may be lost in the form of gaseous products. Therefore, the mass of copper before and after melting will remain the same.

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