Thermal expansion is the tendency of matter to change in volume in response to a change in temperature. When a material is heated, its particles vibrate faster and take up more space, causing the material to expand.
Thermal expansion is measured using the coefficient of thermal expansion (CTE), which is a ratio of the change in length or volume of a material to the original length or volume at a specific temperature. It is usually expressed in units of parts per million per degree Celsius (ppm/°C) or parts per million per degree Kelvin (ppm/K).
The formula for calculating percent change in density due to thermal expansion is: [(final density - initial density) / initial density] x 100%. This calculates the percentage change in density based on the change in volume of a material due to thermal expansion.
Some common examples of thermal expansion in everyday life include the expansion and contraction of bridges, roads, and railway tracks due to temperature changes, the breaking of glass bottles when hot liquid is poured into them, and the popping of popcorn kernels when heated.
Thermal expansion is an important factor to consider in engineering and construction, especially in structures made of materials such as concrete, steel, and glass. Engineers and architects use CTE values to determine how much a material will expand or contract with temperature changes and design structures accordingly to prevent damage or failure.