In which year did Robert Brown observe the zigzag movement of colloidal particles in solution?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. 1827.
- Robert Brown observed the zigzag movement of colloidal particles, known as Brownian motion, in the year 1827.
- He observed this random motion while studying pollen grains suspended in water, although the phenomenon applies to all colloidal particles in a fluid.