In which part of the water cycle does water vapor cool and form water droplets in the clouds? Collection
Condensation
Evaporation
Precipitation

Evaporation

Explanation: Evaporation is the process by which heated liquids converts to gas which transform to damp air which later come as rainfall

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.