Question

Some logs of wood had to be used in a fireplace. The logs were cut into smaller pieces and burned in the fireplace. After one hour, when the logs had completely burned out, a powdery residue in the form of ash was left behind. Using the table below, which row correctly describes the changes that took place? (1 point)

Changes in Burning Logs

Change Cutting logs Burning logs

1 Physical Physical

2 Chemical Chemical

3 Chemical Physical

4 Physical Chemical

Answer 1

The correct row that describes the changes that took place when the logs were used in the fireplace is:

3 Chemical Physical

First, the logs were cut into smaller pieces, which is a physical change. Then, when they were burned in the fireplace, a chemical change occurred as the wood underwent combustion, and the logs were transformed into ash. Finally, the resulting powdery ash residue is a physical change, as it is still a solid, but the chemical composition has changed.