Question

Which of the following pairs will not exhibit diffusion?
A) Hydrogen, oxygen
B) Oxygen, water
C) Salt, sand
D) Sugar crystals, water

Answer 1

Hint : Diffusion is a very important process in the living organisms, it is defined as movement of substance from region or area of high concentration to region or area of low concentration. It is observed in liquids and gases. This concept is widely used in biology, physics, chemistry, economics etc. Example-Oxygen and Carbon dioxide diffuse into our body cells due to diffusion or we observe that when anybody sprays a little of perfume or sanitizer it gets diffused in the room and hence we observe its smell.

Complete Step By Step Answer:
The various factors affecting diffusion rates are-
(a) Temperature (b) concentration (c) distance (d) material.
Diffusion is of 2 types-
1. Simple diffusion-It is movement without any external support of transport proteins. Example-Movement of non-polar ions in and out of the cells.
2. Facilitated diffusion-It is movement from high to low concentration with the help of carrier or transport proteins. Example-Movement of glucose and amino acids in and out of the cell.
In the above given examples in all the pairs we have got at least 1 or more gaseous or liquid component that aids in diffusion except for salt and sand which are both solid in nature and thus will not exhibit the process of diffusion.
(C) Salt, sand is the correct option

Note :
There is another such process termed as Osmosis in which there is movement of solvent molecules from the region of low to high concentration through semi permeable membrane. Example-The absorption of water by plant roots in soil, Dialysis of kidney in the excretory system.