One approximation of this quantity involves taking the limit of the integral [read slowly] “x to the fourth times e to the x, [pause] over the quantity e to the x minus one squared” in a model of this quantity that sets a namesake temperature proportional to the cube root of “six pi squared times number density”. Einstein’s model of this quantity with a lattice of 3D QHOs fails to account (-5[1])for the cubic temperature dependence of this quantity observed in the Debye (“duh-BYE”) model. (10[1])This quantity’s high-temperature value is three times the ideal gas constant according to the Dulong–Petit law. The adiabatic index is the ratio between this quantity’s constant-volume and constant-pressure forms. For (-5[1])10 points, one calorie per gram per degree (10[1])Kelvin (0[1])is water’s value (10[4])of what quantity, which measures how much heat it takes to increase an (10[1])object’s temperature? ■END■