Question

Brownian movement explains the \textit{property of colloidal solutions:}

• A. Optical
• B. Electrical
• C. Kinetic
• D. Mechanical

Hint:

Brownian motion is a result of the kinetic energy of particles in a colloidal solution.

Answer 1

The Correct Option is C

Think of tiny dust particles dancing about randomly in a beam of sunlight coming through a window. That random dancing motion is a familiar, visible version of Brownian movement.

1. Optical: the sunbeam itself, lighting up the dust so it can be seen, is the optical part of the picture, but the actual dancing motion of the dust is a separate effect from just being lit up.
2. Electrical: nothing about the dust particles being pushed around by air molecules involves electric charge, so this option does not describe the dancing motion.
3. Kinetic: the dust particles dance because invisible air molecules are constantly colliding with them, transferring their kinetic energy and knocking them in random directions. That is exactly Brownian movement, and it is a kinetic effect.
4. Mechanical: this would suggest some deliberate physical force or structure at work, not the random molecular collisions actually causing the motion.

Since the dancing dust is driven by random molecular collisions transferring kinetic energy, Brownian movement explains the kinetic property of colloids.

Answer 2

Colloids have several distinct properties, each tied to its own defining phenomenon. Match Brownian movement to the correct one by naming what each property is actually about.

1. Optical: this property is about how colloids scatter light, the Tyndall effect, which is a separate phenomenon from particles physically moving around.
2. Electrical: this property is about the charge carried by colloidal particles, responsible for phenomena like electrophoresis, unrelated to random particle motion.
3. Kinetic: this property is about the motion of particles due to their own energy and collisions with solvent molecules, which is precisely what Brownian movement describes.
4. Mechanical: colloids are not generally described by a distinct mechanical property in this classification, and nothing about random particle motion fits under mechanical strength or rigidity.

Brownian movement is about particle motion driven by energy and collisions, so it explains the kinetic property, making that the correct answer.