Question

1. a family goes camping and creates a fire to roast marshmallows. the next morning, the kids notice that the logs are no longer there, and all that remains are ashes. which best explains why the ashes from a log are evidence of a chemical change? a the color of the wood changed from brown to gray. b. the wood breaks down into smaller matter when burned. c. the ashes cannot be put back together to create a log again. d. something was added to the log, and it cannot be removed. 20. which statement best describes why baking a cake is an example of a chemical change? a the process takes place in an oven. b. the process requires heat energy. c. the process cannot be reversed. d. the process can be repeated.

Explanation:

1. A chemical change results in the formation of new substances with different chemical properties, and it is irreversible. The fact that the ashes cannot be put back together to form the original log shows a chemical change has occurred. Color - change (A) and breaking into smaller matter (B) can be physical changes. Option D is not a correct description of the chemical - change in this context.
2. Baking a cake is a chemical change because new substances are formed with different properties, and the process is irreversible. Just taking place in an oven (A) or requiring heat energy (B) does not necessarily mean it's a chemical change. The ability to be repeated (D) is not related to whether it's a chemical change or not.

Answer:

1. C. The ashes cannot be put back together to create a log again.
2. C. The process cannot be reversed.