What does water vapor need in order to condense?

Water vapor requires a surface to condense upon due to the process of condensation, which is where water vapor transitions into liquid water. This process occurs when the vapor cools down to its dew point and needs something solid or liquid—like dust, pollen, or the surfaces of objects—on which the molecules can cling together to form liquid droplets. These surfaces provide a site for the water vapor molecules to gather and coalesce, allowing condensation to occur.

The other factors mentioned in the incorrect options, such as high temperatures or low pressure, do affect condensation but do not directly provide the mechanism for it to occur. High temperatures actually promote the maintenance of vapor states rather than encouraging condensation. Similarly, while low pressure can influence temperature and state changes in the atmosphere, it is not a requirement for condensation to take place. Air turbulence can relate to mixing and agitation of air, but again, it does not specifically provide the necessary surface for condensation. Therefore, the presence of a surface is the key factor that enables water vapor to condense effectively.