Which of the following is an example of a change of state?
Answer
Snow blows to form snow drifts.
Sodium metal and chlorine gas form salt crystals.
Dry ice disappears.
Grilling a steak turns it brown.
The correct answer is "Dry ice disappears."
To determine the correct answer, it is important to understand what a change of state is. A change of state refers to a physical change that occurs when matter transitions from one state to another. There are three common states of matter: solid, liquid, and gas.
In the given options, three out of the four options involve the formation of new substances or a change in appearance, rather than a change of state.
- "Snow blows to form snow drifts" refers to the wind causing snow to accumulate in specific areas, but it does not involve a change in the state of snow itself.
- "Sodium metal and chlorine gas form salt crystals" describes a chemical reaction, where sodium and chlorine combine to form a new substance, salt. This is not a change of state, but a chemical change.
- "Grilling a steak turns it brown" also represents a chemical change due to the Maillard reaction, which causes browning of the steak's surface. Again, this is not specifically a change of state.
On the other hand, "Dry ice disappears" is an example of a change of state. Dry ice is the solid form of carbon dioxide, and when it undergoes a change of state from solid to gas, it directly disappears without going through a liquid phase. This process is called sublimation, where a substance transitions directly from a solid to a gas state.
Therefore, the correct example of a change of state from the given options is "Dry ice disappears."