Gases may be distinguished from other forms of matter by their :

Join Our Telegram Channel

lack of colour.

ability to flow.

inability to form free surfaces.

ability to exert a buoyant force.

Answer is Right!

Answer is Wrong!

This question was previously asked in

UPSC CAPF – 2010

Download PDF Attempt Online

Gases may be distinguished from other forms of matter by their inability to form free surfaces.

– Solids have fixed shape and volume. Liquids have fixed volume but take the shape of the container from the bottom up, forming a free surface under gravity. Gases take the shape and volume of the entire container.
– Gases expand to fill whatever container they are in, meaning they do not form a distinct boundary or “free surface” in the way liquids do.
– Lack of colour (A) is not universal for gases (e.g., NO2 is brown).
– Ability to flow (B) is characteristic of both liquids and gases (they are both fluids).
– Ability to exert a buoyant force (D) is also characteristic of both liquids and gases (both are fluids).

The defining characteristics of gases at a macroscopic level include: they have no fixed shape or volume, they are easily compressible, and they diffuse readily. The inability to form a free surface is a direct consequence of their molecules having high kinetic energy and weak intermolecular forces, causing them to spread out and occupy the entire volume of the container.

More similar MCQ questions for Exam preparation:-