Multiple Choice Identity the best answer on the given questions. 90- 1. a. a. C. There are several diferences between chemical and physical changes which process is an example of chemical change? Steam rising from a boiling pot of soup A metal railing rusting in dump water Alcohol evaporating from a cotton swap d. A piece of wood shrinking as it dries out 2. Which process is an example of physical change? burning C. flattening brusting d. decomposing 3. Which of the following changes is generally the most difficult to reverse? a. change in state chemical change b. physical change d. change in temperature 4. Chemical change result in new substances, but physical change do not. Which process is a chemical change? a. baking a cake c. heating a cup of tea b. chopping a tree d. drying clothes in the dryer 5. Which of the following can air pollution harm its health and comfort? a. plants b. materials c. humans d. all of the above 6. Which of the following are common sources of air pollution? a. motor vehicles b. wood heaters C. fires d. all of the above ​