Anders dips a steel wire into a solution of copper sulfate and then puts it into a flame, recording his            that the flame turns green.

Anders' observation that the flame turns green upon dipping a steel wire into a solution of copper sulfate and then placing it in a flame indicates a chemical reaction is taking place. The green flame is characteristic of the presence of copper ions in the solution. When the wire is coated with copper sulfate, the copper ions are heated, and they emit light at specific wavelengths, giving rise to the green color.

This occurs because when the copper ions are excited by the heat of the flame, they move to a higher energy state. Upon returning to their ground state, they release energy in the form of light. The specific color of the flame directly corresponds to the energy difference between these states and is a result of the emission spectrum of copper.

In summary:

1. Copper Sulfate Solution: The wire dipped in copper sulfate acquires copper ions.
2. Heat Exposure: The flame's heat excites the copper ions.
3. Color Emission: Returning to a lower energy level, copper ions emit green light.

Thus, Anders' experiment serves as a practical demonstration of flame tests used for identifying metal ions based on the colors they emit when heated.