What do these two changes have in common?
compost rotting
cooking a pancake
A: Both are caused by heating.
B: Both are only physical changes.
C: Both are chemical changes.
D: Both are caused by cooling.
Step 1: Think about each change.
Compost forms from the remains of plants and animals, such as vegetable scraps and egg shells. Compost rotting is a chemical change. As the compost rots, it breaks down and turns into a different type of matter.
Cooking a pancake is a chemical change. Pancakes are made from pancake batter. A cooked pancake is a different type of matter than pancake batter. Pancake batter is wet and slippery. Cooked pancakes are fluffy and can be good to eat!
Step 2: Look at each answer choice.
Both are only physical changes.
Both changes are chemical changes. They are not physical changes.
Both are chemical changes.
Both changes are chemical changes. The type of matter before and after each change is different.
Both are caused by heating.
Cooking is caused by heating. But compost rotting is not.
Both are caused by cooling.
Neither change is caused by cooling.