boiling
A liquid gains energy when it is heated. The particles move more quickly as the temperature is increased. Eventually, the particles have enough energy to completely break the forces holding them together. The particles are now able to move freely and far apart. A gas is formed. This process is called boiling.
The temperature at which boiling happens is called boiling point. The boilling points of some common substances are given in Table 1.2. lt is always understood that these boiling points apply at normal