A molecule takes 3.0 seconds to diffuse across a membrane. If the thickness of the membrane is doubled, then how long does it take the molecule to diffuse across the thicker membrane?
A) 30 s
B) 24 s
C) 20 s
D) 18 s
E) 12 s

Question

Quizplus · Accepted Answer

Diffusion time is proportional to the square of the distance. If the thickness is doubled, the time increases by a factor of four (2^2). Therefore, 3.0 s * 4 = 12 s.

A Molecule Takes 3