Effect of doubling kinetic energy on phase transitions The kinetic energy of the molecules in a sample of $\ce{H2O}$ in its stable
  state at $ \pu{–10 ˚C}$ and $\pu{1 atm}$ is doubled. What are the initial and final phases? [US National Chemistry Olympiad, 2010]


Answer: $\ce{solid -&gt; gas}$

My attempt: Since water freezes at $\pu{0^\circ C}$ at $\pu{1 atm}$, then the water clearly begins in a solid state. In the solid state, most of the atoms are locked within a crystal of hydrogen bonds and therefore have extremely small kinetic energies. Thus, doubling the kinetic energy should not have any impact on the phase, since gases have significantly more kinetic energy than the solid/liquid phase.

Why does the solid have enough kinetic energy such that doubling it results in sublimation?
The atoms are not locked in place.   They vibrate back and forth.  They do so with plenty of velocity and thus kinetic energy, even though the vibrations switch back and forth so rapidly that the atoms do not travel a large distance in any one direction.