lume. In contrast, the space between gas the volume of a solid or liquid, those varia expansion: A solid does not take the shap pand to fill it. A gas takes the shape of its c None • Density: In both solids and liquids, the molecules are held very closely together and therefore their densities are about the same. In gases, there is space between the molecules. • Molecular movement and order: The molecules in solids are arranged in a regular pattern that does not allow for diffusion, although does allow for vibrations. The arrangement of molecules in a liquid, although not completely random, is not completely fixed. Molecules in a gas are randomly arranged and move very quickly. Gases diffuse quickly in comparison to liquids. • Compressibility and thermal expansion: Since the molecules in solids and liquids are already very close together, applying pressure does not greatly affect the volume. In contrast, the space between gas molecules allows for a great deal of compressibility. Although temperature changes will cause slight variations in the volume of a solid or liquid, those variations are negligible compared to the thermal expansion of a gas. • Shape and expansion: A solid does not take the shape of its container, nor does it expand to fill the container. A liquid takes the shape of its container but does not expand to fill it. A gas takes the shape of its container and expands to fill it. Part A Sometimes when we bake a potato without poking holes in the skin, the potato will burst. Why does this occur? • The air and water vapor inside the potato is expanding. • The flesh inside the potato is expanding. • The skin of the potato is expanding. Submit Part B B. Word Masteri… Periodic Tab Spotify… 73°F 5:45 PM 11/30/2021
The Correct Answer and Explanation is:
Correct Answer (Part A):
• The air and water vapor inside the potato is expanding.
Explanation (Part B):
When a potato is baked without poking holes in its skin, it can sometimes burst. This happens because of the thermal expansion of the water and air inside the potato. As the potato heats up in the oven, the moisture inside the potato (which includes both water and air trapped in the cells) turns into steam (water vapor). Gases expand significantly when heated, much more than solids or liquids. According to the properties of gases, they have high compressibility and undergo significant thermal expansion because the gas molecules are far apart and move rapidly when heated.
As the water inside the potato heats up and changes into steam, it increases the internal pressure. Normally, if the potato’s skin has small holes (poked with a fork, for example), the steam can escape easily, relieving the pressure. But if the skin is intact and unpierced, it acts like a barrier—a sealed container. Since a gas (steam) always tries to expand to fill the volume available to it, pressure builds up inside the potato.
Eventually, the pressure may exceed the strength of the potato’s skin. At that point, the potato bursts open to release the trapped steam and relieve the internal pressure.
This is a real-world example of how gas behavior—including molecular motion, expansion, and compressibility—can have visible, even explosive, effects. It also shows that while solids (like the potato’s skin) don’t expand much and are not easily compressible, gases do, and ignoring this can lead to bursting.
Therefore, poking holes before baking provides an outlet for the steam, preventing a pressure buildup and allowing for safe cooking.
