Aitken particles are

Solution (By Examveda Team)

Aitken particles are activated in humid air, cloud's condensed nuclei and Hygroscopic particles.
Aitken particles have been defined as those airborne particles having radii less than 0.1 m but larger than those of molecules and small ions.
Those with a particle size between 5.0 × 10^-3 and 0.2 μm are called Aitken nuclei, those with a particle size from 0.2 to 1 μm are called large particles, and those with a particle size greater than 1 μm are called giant particles.