Which characteristics define a liquid? A. definite volume, fixed shape, and no molecular motion B. definite volume, variable shape, and least molecular motion C. indefinite volume, variable shape, and high molecular motion D. definite volume, variable shape, and high molecular motion
The Correct Answer and Explanation is:
Correct Answer: D. definite volume, variable shape, and high molecular motion
Explanation:
Liquids are one of the three primary states of matter, alongside solids and gases. A liquid is characterized by having a definite volume but no fixed shape. This means that a liquid maintains a consistent volume regardless of the container it is in, but it takes the shape of the part of the container it occupies.
Unlike solids, which have both a definite shape and volume, the particles in a liquid are not held in rigid positions. The molecules in a liquid are close together but not in fixed locations. They can move past one another, allowing the liquid to flow. This molecular motion in liquids is more significant than in solids but less than in gases. The particles in a liquid have enough energy to slide around each other, which gives the liquid the ability to conform to the shape of its container.
Liquids also exhibit surface tension and viscosity, which are physical properties resulting from intermolecular forces and molecular motion. Surface tension allows small objects to rest on the surface of a liquid without sinking, while viscosity refers to the liquid’s resistance to flow. These properties further reflect the dynamic and interactive behavior of liquid molecules.
Importantly, a liquid’s volume remains constant under standard conditions, unless temperature or pressure is significantly altered. Heating a liquid generally increases molecular motion, possibly converting it into a gas through evaporation or boiling.
In summary, the key characteristics of a liquid include definite volume, variable shape, and moderate to high molecular motion compared to solids. These traits distinguish liquids from both gases, which have neither definite volume nor shape, and solids, which have both. Hence, option D accurately describes a liquid.
