JAMB - Physics (2025 - No. 72)
A collection of condensed suspended dust particles in the air constitute
Cloud
fog
Mist
Rain
Förklaring
Clouds are collections of condensed water droplets or ice crystals suspended in the air, but high above the ground (typically hundreds of meters to kilometers up).
Fog is the same phenomenon (condensed suspended droplets, often with dust), but at ground level, reducing visibility.
The question specifies "in the air" near the surface (implied by dust particles and suspension context), so fog is correct, not cloud.