1. Air resistance: Air resistance is the force that opposes the motion of an object through the air. The greater the air resistance, the slower the object will move. This can be demonstrated by dropping two objects of different weights from the same height. The heavier object will fall faster because it experiences less air resistance.

2. Wind: Wind is the movement of air. It can be caused by differences in air pressure, temperature, or the rotation of the Earth. Wind can be felt on the skin, and it can also be seen by observing the movement of leaves and trees.

3. Clouds: Clouds are formed when water vapor in the air condenses into tiny droplets. These droplets can then freeze into ice crystals. Clouds can be seen in the sky, and they can also be used to predict the weather.

4. Evaporation: Evaporation is the process by which liquid water turns into water vapor. This process can be seen by observing a puddle of water on a hot day. The puddle will gradually disappear as the water evaporates into the air.

5. Condensation: Condensation is the process by which water vapor turns into liquid water. This process can be seen by observing the formation of dew on a cold morning. The dew forms when water vapor in the air condenses on the cool surfaces of plants and objects.