Heating and Cooling During Phase Changes

Heating and cooling can change a substance from one state of matter to another. These phase changes depend on internal energy, which is the total kinetic energy of particles and the potential energy from their interactions. In the condensed phases, stronger intermolecular forces and the pressure on the substance affect that ...

物质通常以固态、液态或气态存在。在气体中，高能分子运动迅速且彼此间距较远，因此分子间的吸引力较弱。

温度、压力或两者的变化均可引发物态之间的相变，或称物相变化。

在这些相变过程中，能量在不改变温度的情况下流入或流出系统。

一摩尔物质完全发生相变所需的能量变化即为该相变的摩尔焓变。

压缩或冷却气体使其分子更难相互远离，从而转变为更致密、更不易压缩的液体。

降低液体的温度会减少其动能，使其转变为不可压缩固体的紧密排列状态。