Which of the following changes represents a physical change,

Last updated: 7/10/2022

Which of the following changes represents a physical change, rather than evidence of a chemical reaction? When a piece of zinc metal is placed in a solution of HCI, bubbles begin to form, and the zinc begins to dissolve. When solid ammonium carbonate, (NH 4)2CO3, is heated, the solid disappears, and gaseous ammonia (NH3), carbon dioxide (CO2), and water (H2O) are formed. When dry ice (solid CO2) is allowed to stand at room temperature, gaseous CO2 is formed. When a solution of KI is mixed with a solution of Pb(NO 3)2, a yellow solid is formed. When a piece of copper wire is placed in a solution of AgNO3, a silvery solid begins to form on the surface of the wire, and the solution turns blue.