Evidence for Kinetic Theory: Brownian Motion

What is Brownian Motion?

Brownian motion is the random movement of particles suspended in a fluid (liquid or gas) resulting from their collision with fast-moving molecules in the fluid. This phenomenon provides evidence for the kinetic theory of matter, which states that matter is made up of tiny particles in constant motion.

Key Characteristics of Brownian Motion

• Random Movement: Particles move in a zigzag or erratic path.
• Collisions: Caused by collisions with molecules of the fluid.
• Observable: Can be observed under a microscope, especially in smoke particles in air or pollen grains in water.

How Does Brownian Motion Support Kinetic Theory?

• Particle Nature of Matter: Demonstrates that matter consists of small particles.
• Constant Motion: Shows that these particles are in constant, random motion.
• Energy Transfer: Movement is due to energy transfer from fluid molecules to the suspended particles.

Examples of Brownian Motion

• Smoke in Air: Smoke particles move randomly when observed under a microscope.
• Pollen in Water: Pollen grains suspended in water exhibit random motion.