Which of these changes produces a chemical change?
A chemical change example
Chemical changes occur when substances react to form new substances. These changes involve the breaking and forming of chemical bonds. Let's look at an example to understand better.
Options:
A. Lava cools and changes from a thick fluid to solid rock. This is a physical change as the state of the substance changes without forming a new substance.
B. A large rock is crushed into gravel. This is also a physical change as the size and shape of the rock change, but no new substances are formed.
C. Limestone slowly dissolves in water and forms a cave. Dissolving is a physical change as the substance disperses in the solvent, but no new substances are created.
D. A stone fizzes and forms a gas when acid is dropped on it. This is a chemical change as a new substance (gas) is formed due to the reaction between the acid and the stone.
Answer:
b
Dissolving is a chemical change
Which of the following is an example of a chemical change? A chemical change example is when iron rusts, forming a new substance (iron oxide) due to its reaction with oxygen in the air. This change involves a chemical reaction that results in the formation of a different substance with new properties.