Final answer:
The coefficient of linear expansion (α) is the change in an object's length per unit length per 1°C temperature change and is expressed in 1/°C or 1/K. The coefficient of volume expansion (β) refers to the change in volume per unit volume per 1°C temperature change. These coefficients vary by material and are used to calculate changes in dimension due to temperature shifts.
Step-by-step explanation:
Thermal expansion is defined as the tendency of matter to change in shape, area, and volume in response to a change in temperature. When a solid is heated, it expands in all directions. The coefficient of linear expansion (a) is defined as the change in length per unit length per 1°C change in temperature. This coefficient depends on the material and, to some extent, the temperature of the material. The units of a may be expressed either as 1/°C or 1/K, since the kelvin and degree Celsius scales increment equally. The equation ΔL = αLΔT is accurate for small changes in temperature. The equation can also be used for larger changes in temperature if an average value of a is used.
The coefficient of volume expansion (β) defines the change in volume per unit volume per 1°C change in temperature. It's essential to remember that volume expansion is defined for liquids since the shape of liquids conforms to their containers, making linear and area expansion of liquids impractical to define. Therefore, only β is typically used for liquids.