Answer: 1 to 1000 nm.
- A less than 1 nm
- B 1 to 1000 nm
- C more than 1 micrometre
- D close to 1 millimetre
Correct answer: B. 1 to 1000 nm
Explanation: Colloidal particle sizes lie between 1 and 1000 nm, larger than in true solutions but smaller than in suspensions.
A typical adsorption isotherm: x/m (mass adsorbed per gram of adsorbent) rises steeply at low pressure, then flattens into a saturation plateau as the adsorbent surface fills up.
Concept context
Explore the chemistry that happens at interfaces, from catalysts that speed up industrial reactions to colloids like milk, smoke, and gels that surround us every day.