As part of a demonstration, Mr. Wadlow took flat copper wire and wrapped it around a pencil to make a coil. Then, he placed the coiled copper wire into a beaker of clear silver nitrate solution. After thirty minutes, gray particles collected on the copper, and the solution turned blue. What resulted from the combination of the copper wire and the silver nitrate solution?

Question

As part of a demonstration, Mr. Wadlow took flat copper wire and wrapped it around a pencil to make a coil. Then, he placed the coiled copper wire into a beaker of clear silver nitrate solution. After thirty minutes, gray particles collected on the copper, and the solution turned blue. What resulted from the combination of the copper wire and the silver nitrate solution?
A. 
a physical change, as demonstrated by the coiled wire

B. 
a chemical change, as demonstrated by the coiled wire

C. 
a physical change, as demonstrated by the gray particles and the blue solution

D. 
a chemical change, as demonstrated by the gray particles and the blue solution

GPT-4o mini · Answer

The correct answer is: **D. a chemical change, as demonstrated by the gray particles and the blue solution.** This demonstrates a chemical change because a new substance (silver) is formed as the gray particles, and the solution changes color (blue) due to the formation of copper(II) nitrate as copper displaces silver in the solution. The change in color and the formation of solid particles indicate a chemical reaction has occurred.