What best describes the shape and volume of a gas?
A) indefinite shape, indefinite volume
B) indefinite shape, definite volume
C) definite shape, indefinite volume
D) definite shape, definite volume
The Correct Answer and Explanation is:
The correct answer is A) indefinite shape, indefinite volume.
Explanation:
To understand the properties of gases, it is important to recognize how they behave in relation to shape and volume compared to solids and liquids.
- Indefinite Shape:
- Gases do not have a fixed shape. This is because gas molecules are widely spaced and move freely in all directions. They will expand to fill the shape of the container they are in, whether it is a round bottle, square tank, or irregularly shaped vessel. The gas particles move rapidly and are in constant motion, so they do not “take” a specific shape like solids or liquids.
- In contrast, solids have a definite shape because their particles are closely packed and only vibrate in place, while liquids have a definite volume but no definite shape, since their particles can move past one another but still remain somewhat close together.
- Indefinite Volume:
- Gases also do not have a definite volume. The volume of a gas is highly dependent on the container’s size. When a gas is in a container, the particles will spread out and occupy the entire volume available to them. If the gas is placed in a larger container, its volume increases because the gas particles will expand to fill the space. Similarly, if the volume of the container is reduced, the gas particles will compress into the smaller space.
- Liquids and solids, on the other hand, have a definite volume. The particles in liquids are close enough to maintain a consistent volume, while solids have tightly packed particles that hold their shape and volume.
Summary:
- Gases have indefinite shape because they expand to take the shape of their container.
- Gases have indefinite volume because they expand to fill the entire volume of the container they occupy.
Thus, the correct answer to the question is A) indefinite shape, indefinite volume.