But, if you are serious about learning Italian - and even before you buy or subscribe to any expensive courses (except, obviously, GamesforLanguage.com's Italian Story, which is FREE!) - you may want to learn more about Benny's approach by clicking on his explanation of Why Italian is easy!.
Coefficient of thermal expansion. The coefficient of thermal expansion describes how the size of an object changes with a change in temperature. Specifically, it measures the fractional change in size per degree change in temperature at a constant pressure. Several types of coefficients have been developed: volumetric, area, and linear.
Example - water is a liquid where the volumetric expansion coefficient changes a lot with temperature. Water has its highest density and smallest volume at 4oC (39.2 oF). The volumetric coefficient for water is negative below 4oC and indicates that the a volume decreases when temperature moves from 0oC (32 oF) to 4oC.