Question

The absolute zero is the temperature at which :

• A. water freezes.
• B. all substances exist in solid state.
• C. molecular motion ceases.
• D. ice melts.

Answer 1

The correct option is C

molecular motion ceases.

At absolute zero (i.e. 0 K) $v_{rms}$ becomes zero. Absolute zero is the lowest possible temperature where no heat energy remains in a particle and the particle does not has enough energy to move therefore its motion ceases at molecular level.