The random motion of particles in a fluid due to temperature is known as which type of motion?

The random motion of particles in a fluid due to temperature is known as which type of motion?

• A. Random motion
• B. Brownian motion
• C. Thermal motion
• D. Stochastic motion

Answer: (B)

Brownian motion is the erratic movement of small particles suspended in a fluid caused by continuous, random collisions with the fluid’s molecules that are moving due to temperature. This phenomenon, observed when Brown looked at pollen grains in water, shows how countless molecular impacts from all directions produce a jittery path. While thermal motion describes the general motion of particles due to temperature, and random or stochastic motion refer to randomness in a broader or mathematical sense, Brownian motion names this specific observable wandering of suspended particles. So this term best captures the described effect.

Brownian motion is the erratic movement of small particles suspended in a fluid caused by continuous, random collisions with the fluid’s molecules that are moving due to temperature. This phenomenon, observed when Brown looked at pollen grains in water, shows how countless molecular impacts from all directions produce a jittery path. While thermal motion describes the general motion of particles due to temperature, and random or stochastic motion refer to randomness in a broader or mathematical sense, Brownian motion names this specific observable wandering of suspended particles. So this term best captures the described effect.