Lithospheric plates move apart under the ocean floor.
Explanation:
The mantel convection currents movement occurs it stretches the crust apart. The heat from convection currents makes the the Earth crust molecules less stable because the heat makes them move apart and shake on molecular level which makes crust more flexible.
Particles in a gas have more energy than particles in a liquid. Because in gaseous state particles are free to move around due to which kinetic energy of molecule or gas increases and hence overall energy increases
