How Does Air Temperature Affect Different Surfaces?

Metal

• Air temperature can make metal surfaces expand or contract. Warm air temperatures can make the molecules of metals gain more kinetic energy, making expansion possible. When the air temperature returns to normal, the kinetic energy disperses, allowing the metal to return to its normal size. Engineers often consider this phenomenon when using metals in construction, like adding gaps in metal bridges to provide allowance when it expands during the hot season.

Soil

• Although air temperature only affects the shallow layer of soil or the topsoil, it has significant effect on how well plant and other life forms will thrive in the soil. For example, soil exposed to cold air temperature is not good soil for seeds to germinate. Aside from inhibiting seeds from growing, the development of plants also slows down in cold weather. In hot weather, hot air sucks out the moisture on the topsoil, depriving living organisms of the necessary water they need.

Water

• Hot air temperatures allow water to evaporate, creating a humid environment, while cold air temperatures can freeze it if it's cold enough, creating dry air without moisture. During winter, tops of lakes and rivers can sometimes freeze. If the water surface does not contain a large amount of water, a very hot air temperature can suck out all the water and turn it into vapor.

Plastic

• Plastics also expand and contract, depending if the air temperature is hot or cold. Plastics become more elastic and expand when exposed with hot air, while they contract and becomes brittle when exposed to cold air. Just like metals, molecules in plastic also receive extra kinetic energy when exposed with hot air, while they lose some when exposed to cold air.