Question

For frost to be on the grass in the morning, the water vapor in the air must ____

Answer 1

Answer:

Condense and freeze

Explanation:

During a warm day , the water from the ground gets evaporated into the air

During the evening,the temperature of the ground drops down as heat  is radiated from ground to the air continues

At a point called the "dew point" ,the air in the moisture becomes so great that it can not hold more of it .The condensed air allows the dews to form on the surfaces that are away from the ground (that radiates heat) .grass and objects etc