Which description best matches a gas?

Which description best matches a gas?

• A. Particles are tightly packed and vibrate in place
• B. Particles move more freely past each other but aren't free to move far apart
• C. Particles are far apart and have no definite shape or volume
• D. Particles are charged at very high temperatures

Answer: (C)

Gases have particles that are far apart and move quickly, with only weak attractions between them. This spacing and motion mean they don’t have a definite shape or volume; they spread out to fill whatever container they’re in and can be compressed to fit into a smaller space. That’s different from solids, where particles are tightly packed and vibrate in place, giving solids a definite shape and volume, and from liquids, where particles can flow past one another but maintain a definite volume. So the description that says particles are far apart and have no definite shape or volume best matches a gas.

Gases have particles that are far apart and move quickly, with only weak attractions between them. This spacing and motion mean they don’t have a definite shape or volume; they spread out to fill whatever container they’re in and can be compressed to fit into a smaller space. That’s different from solids, where particles are tightly packed and vibrate in place, giving solids a definite shape and volume, and from liquids, where particles can flow past one another but maintain a definite volume. So the description that says particles are far apart and have no definite shape or volume best matches a gas.