A fine example of this is the integration of basic pneumatics into the middle or high school science program. There are any number of ways that pneumatics may be integrated into either an earth or physical science program. Air has mass. There are spaces between air molecules. Air's mass and volume determine its density.
Air density can change.
Air density is affected by changes in altitude and temperature. Warm air becomes less dense and rises while cold air becomes more dense and settles. Winds are produced when cooler, sinking air moves in to replace warmer rising air. Major wind systems affected early exploration of the earth. Wind systems and jet streams' direction of movement are affected by the earth's rotation.