Question

gravitational force keeping pulling objects towards earth but water molecules are remaining in the atmosphere layer.can anyone explain the reason behind it?

Answer 1

I hope you are familiar with the concept of gases. Although matter such as liquid and solid tend to fall down when they are dropped during a free fall or under the action of gravity. But gases tendency to have go up. Lets take example of incense stick which is lit up. Remember the smoke it also rises up because the particles has more kinetic and thermal energy as compared to other states of matter. Same occurs with water vapour too.