ANSWER 1
- Formation of a gas
- Formation of a precipitate
- Change in color
- Change in temperature
- Change in odor
The presence of these signs indicates that a chemical change has taken place. These signs show that the substances involved have undergone a chemical reaction, resulting in new substances being formed.
ANSWER 2
As the pancakes are cooked, they change both physically and chemically. Physically, the pancakes change in color, texture, and shape as they are heated. Chemically, the batter undergoes a reaction with the heat, causing the pancakes to brown and develop a different taste.
ANSWER 3
The appearance of the iron garden tools with spots of a reddish-brown, flaky substance indicates a chemical change has taken place. This is likely the result of oxidation of the iron, which forms iron oxide (rust). Rust formation is a chemical change as new substances are formed.
Short Answer
QUESTION 1
List the signs that indicate a chemical change has taken place. What does the presence or absence of these signs tell you about a chemical change?
QUESTION 2
Maggie is making pancakes. How do the pancakes change as they are cooked? Are they changing physically or chemically?
QUESTION 3
Iron garden tools were left outside over the winter. When found, they appeared dirty with spots of a reddish-brown, flaky substance. Was this a physical or chemical change? How do you know?
1 answer
1 answer