What is/are true regarding most of the medicines.
(A) They are colloidal in nature
(B) Their particle size range from \(1 – 1000 nm\)
(C) They have large surface area
(D) They are easily assimilated
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → A, B, C, D only
A colloid is a heterogeneous system in which particles of size about 1 nm to 1000 nm are dispersed in a medium; such small particles have a very large surface area for their mass.
(A) They are colloidal in nature — Correct. Most medicines are colloidal.
(B) Their particle size range from 1-1000 nm — Correct. This is the size range of colloidal particles.
(C) They have large surface area — Correct. Fine division gives a large surface area per unit mass.
(D) They are easily assimilated — Correct. The large surface area is the reason they are easily assimilated and more effective.
Note: This question is from the pre-rationalised NCERT book (2022-23). The topic is not there in the latest NCERT book (2026-27), and it is also out of the CUET 2026 syllabus.
NCERT (Pre-rationalised edition, 2022-23):
Applications of Colloids – “… Most of the medicines are colloidal in nature. For example, argyrol is a silver sol used as an eye lotion. Colloidal antimony is used in curing kalaazar. Colloidal gold is used for intramuscular injection. Milk of magnesia, an emulsion, is used for stomach disorders. Colloidal medicines are more effective because they have large surface area and are therefore easily assimilated.”