In photograph a, a coil of zinc metal is in a solution of sulfuric acid. In photograph b, a yellow solution of sodium chromate is being added to a colorless solution of silver nitrate. What clues in the photographs indicate that a chemical change is probably occurring.
In photograph a, chemical change is occuring as when a coil of zinc metal is in a solution of sulfuric acid, then the solution starts bubbling, that indicates a chemical change.
In photograph b, a yellow solution of sodium chromate is being added to a colorless solution of silver nitrate, that changes the color of the solution to red , that indicates a chemical change.
